Tonga Exports of pebbles, gravel, flint, macadam of slag, tarred macadam to China was US$5 during 2014, according to the United Nations COMTRADE database on international trade. Tonga Exports of pebbles, gravel, flint, macadam of slag, tarred macadam to China - data, historical chart and statistics - was last updated on September of 2026.