Article: In terms of ship categories, Greek companies have 22.6% of the world's tankers and 16.1% of the world's bulk carriers (in dwt). An additional equivalent of 27.45% of the world's tanker dwt is on order, with another 12.7% of bulk carriers also on order. Shipping accounts for an estimated 6% of Greek GDP, employs about 160,000 people (4% of the workforce), and represents 1/3 of the country's trade deficit. Earnings from shipping amounted to €14.1 billion in 2011, while between 2000 and 2010 Greek shipping contributed a total of €140 billion (half of the country's public debt in 2009 and 3.5 times the receipts from the European Union in the period 2000–2013). The 2011 ECSA report showed that there are approximately 750 Greek shipping companies in operation.

Now answer this question: How many of the world's tankers do Greek companies own?
22.6%