Photo taken on May 25, 2018 shows merchant ships and ferryboats at Piraeus port, Greece. Greek shipping remains a global leader in 2018, controlling 20 percent of the global fleet in deadweight tons (dwt), according to the annual report 2017-2018 of the Union of Greek Ship owners released on Thursday. (Xinhua/Chris Kissadjekian)

Photo taken on May 25, 2018 shows cargo ships at Piraeus port, Greece. Greek shipping remains a global leader in 2018, controlling 20 percent of the global fleet in deadweight tons (dwt), according to the annual report 2017-2018 of the Union of Greek Ship owners released on Thursday. (Xinhua/Chris Kissadjekian)

A man walks past a ferryboat at Piraeus port, Greece, on May 25, 2018. Greek shipping remains a global leader in 2018, controlling 20 percent of the global fleet in deadweight tons (dwt), according to the annual report 2017-2018 of the Union of Greek Ship owners released on Thursday. (Xinhua/Chris Kissadjekian)