This is how you can tell if China is lying about its economic data

China just delivered its lowest GDP growth figure in 25 years.

On Monday, China lowered its GDP growth figure to 7.3%, from its January number of 7.4%.

Not only is its growth slowdown freaking out investors, the revision once again throws the accuracy of China's data reporting into the limelight.

It's pretty well-documented on how China's economic data releases provides a conundrum for investors and many don't fully believe whether the government is telling the truth or not.

My colleague Mike Bird pointed this out why Chinese data can be confusing when it comes to painting an accurate picture of what's really going on.

However, speaking to the BBC this morning, Jeremy Penn, chief executive of maritime market data organisation Baltic Exchange highlighted how one of the key ways in determining the health of the Chinese economy is through shipping.

He said that looking at the figures over how much raw materials are being shipped into the country can signal production and consumption rates as shipping data shows the "infrastructure thrust" in the country.

"The position of shipping of raw materials into China is a clear indicator," said Jeremy Penn, chief executive of maritime market data organisation Baltic Exchange to the BBC.

"In the early part of this year, March or April, we saw for the first time in many years a decline in absolute numbers for steel production in China, and that's reflected through now into the import levels for coal and iron ore, and the shipping rates, which are associated with those types of ships."

In other words, you can compare what raw shipping figures are from places like Baltic Exchange with that of the Chinese government reports on production, consumption, and what it says on imports and exports.

Penn added that China's shipping growth slowed down for the first time in 12 years without giving specific figures.