In tonnage terms , the amount of gold used for jewelry plummeted by 35 % between 2005 and 2009 .
以吨数计算,用于珠宝的黄金数量在2005至2009年间累计下降了35%。
Cod is far and away iceland 's most valuable fish , but its stocks are falling : the tonnage caught since the 1990s has been about 2 00000 a year , compared with about 4 00000 in the 1960s .