This is when every serving Supreme Court Justice could retire, based on age, average tenure and if they've said they might quit

• The retirement of Supreme Court Justice Anthony Kennedy means Trump can nominate a conservative for the nation's highest court.
• With half the court aged over 70, further retirements would leave the court open to more conservative leanings.
• The average age the last 11 justices retired at is 80, and their average tenure was 27 years.
• Based on this trend, Ruth Bader Ginsberg could retire very soon, but the other 8 justices are way off.
• Trump has reportedly suggested that Sonia Sotomayor's term could be cut short by her diabetes, but she has pushed back against that.

The announcement on Wednesday that Supreme Court Justice Anthony Kennedy will retire in July has given Trump a chance to choose his replacement - and has left people wondering when other seats on the court might become vacant.

Business Insider has calculated an average retirement age and tenure length for the last 11 justices to retire, going back to Justice Warren E. Burger, who quit in 1986.

The average age of retirement for the past 11 justices, including Kennedy was 80. These justices spent at average of 27 years in the court.

We have averaged the two metrics to reach a ballpark year that the justices could retire based on precedent. It is worth remembering this is a rough prediction and a justice can leave the Supreme Court at any time for any reason.

Scroll down to see where each Supreme Court justice stands - and when the figures suggest their term could end.

Ruth Bader Ginsburg

Age: 85 (5 years past average retirement)

Tenure: 24 years (3 years less than average)

Predicted departure: Last year

Born in 1933, Supreme Court Justice Ruth Bader Ginsburg is now 85 years old - four years than older Kennedy, and five years past the average retirement age.

She took her seat on the Supreme Court in August 1993 after a nomination from Bill Clinton, and is three years shorter than the average tenure.

But Ginsburg told PBS in January that she would adopt the plan of former Supreme Court Justice John Paul Stevens, who retired at the age of 90.

She further suggested that would be sticking to these plans and that she would not retire before the end of Trump's term as president by hiring four full-time law clerks through to 2020 - a move that is not typical for justices who plan on stepping down.

Ginsburg, who has become something of a liberal icon, said in February: "As long as I can do the job full steam, I will be here."

Stephen Breyer

Age: 79 (1 year before average retirement)

Tenure: 23 years (4 years less than average)

Predicted departure: 2021

At 79, Breyer has not made any suggestion that he will retire soon. He is a year younger than the average retirement age, and his tenure is currently four years shorter than the average.

Breyer has been a Supreme Court Justice since August 1994, following a nomination from President Bill Clinton.

As a liberal justice, Breyer may want to continue in office to prevent a conservative pick gaining his seat.

Clarence Thomas

Age: 70 (10 years before average retirement)

Tenure: 26 years (1 year less than average)

Predicted departure: 2024

Highly conservative Supreme Court Justice Clarence Thomas is 70, having served on the court since October 1991 after a nomination from George Bush. He is 10 years younger than the average retirement age, but he started relatively young, so his tenure is now just one year shorter than the average.

When rumors that a Supreme Court justice was to retire emerged, some wondered if Thomas would go instead of Kennedy.

Thomas made no public comment about this. A 2016 report that said he would retire was rejected by his wife, Ginni, on Facebook. She wrote: "IT. IS. BOGUS!"

Samuel Alito

Age: 68 (12 years before average retirement)

Tenure: 12 years (15 years less than average)

Predicted departure: 2032

Alito has been in his seat since January 2006, following a nomination from President George W Bush. At 68, he has not made any public comments that suggest he may retire soon, and he is 12 years younger than the average retirement age, with another 15 years to go before his tenure reaches the average length.

A consistent conservative voter, he laid out a plan for the Supreme Court in 2016 if it won a conservative majority after Trump took office. He may well want to see this agenda through now that Trump has added more conservative justices to the court.

Sonia Sotomayor

Age: 64 (16 years before average retirement)

Tenure: 8 years (19 years less than average)

Predicted departure: 2036

At 64, Sotomayor has only served on the court since August 2009, after a nomination from President Barack Obama. She is 16 years younger than the average retirement age, and her tenure is currently 19 years behind the average length.

But Trump has reportedly said he believes he will be able to replace Sotomayor, citing her health. Trump has talked about Sotomayor's Type 1 diabetes, sources told to news website Axios, saying: "Her health, no good. Diabetes."

Paramedics were called to Sotomayor's house in January, but she went back to work that day following treatment for low blood sugar. She was not hospitalised, Politico reported.

Sotomayor previously described herself as "super vigilant" about her condition.

As with the other liberal judges, she may well want to keep her seat for the near future to prevent it going to a conservative judge.

John Roberts

Age: 63 (17 years before average retirement)

Tenure: 12 years (15 years less than average)

Predicted departure: 2034

At 63, Chief Justice John Roberts is one of the younger members of the court. He only took his seat in 2005, after he was nominated by George W Bush.

Roberts is likely to become the court's swing vote following Kennedy's retirement, as Trump is likely to pick someone more conservative than him, leaving Roberts in an ideological middle between the more conservative and liberal members of the court.

There is no sign Roberts will step down anytime soon.

Elena Kagan

Age: 58 (22 years before average retirement)

Tenure: 7 years (20 years less than average)

Predicted departure: 2039

Age 58, Kagan is a a liberal judge nominated by President Barak Obama and assumed the role in August 2010. She is 22 years younger than the average retirement age and has another 20 years to go before her tenure reaches the average length.

She was outspoken over the court's decision to uphold Trump's travel ban, accusing conservative colleagues of using the First Amendment as "a sword" to influence politics and the economy.

She called some of her colleagues "black-robed rulers overriding citizens' choices," and it is unlikely that she will look to offer her seat to another conservative voice nominated by Trump.

Neil Gorsuch

Age: 50 (30 years before average retirement)

Tenure: 1 year (26 years less than average)

Predicted departure: 2046

Gorsuch only took his seat in April last year. He was nominated by Trump, and, at 50, is the youngest on the court. He has 30 years before he reaches the average retirement age, and another 26 years before he reaches the average tenure length.

The Washington Post reported that Trump talked about rescinding his nomination, and was worried that Gorsuch would not be loyal enough. Trump has disputed these claims. Gorsuch has voted against Trump's administration previously, including deporting immigrants who commit crimes in the US.

Despite this, the young, conservative judge is likely to sit on the court and shape laws for decades to come.