2009, the year after the economy collapsed, was the best year to launch a $1 billion unicorn

There's no question that 2015 was the year of the unicorn - the term for a startup worth one billion dollars or more (once considered so rare, it was like a unicorn).

At the start of 2014, there were about 43 startups, across all industry sectors, that were considered to be worth $1 billion, according to the Wall Street Journal.

At the end of 2015, there are now 144 unicorns, with a total valuation of more than half a trillion dollars ($508 billion), finds CBInsights.

As we reported earlier, 1.3"unicorn" companies have been created every week in 2015.

True, it looks like the unicorn bubble may have popped for some of these companies, with valuations sinking and cash getting harder to raise at such favorable terms.

But what we also learned from the unicorn boom this year, is that the very best time to create a fast growing, valuable company is in the midst of an economic winter.

It turns out that 2009 was the best year to launch a unicorn, according to analys charts from Goldman Sachs.

Remember 2009? The world was reeling from the economic collapse of 2008. The unemployment rate was at a 25-year-high of 8.5% and 2 million jobs were lost in the first quarter.

In that year companies like Uber, Pinterest, Tiny Speck (which would morph into Slack), and Nutanix were launched, among others.

And, although the tech industry has grown the most unicorns, other sectors had their share, too, like real estate (WeWork), Energy (Bloom Energy) and ecommerce (Blue Apron).