| 1970 | 1990 | 2000 | 2005 | 2010 | 2011 | 2012 | 2013 | 2014 | |
|---|---|---|---|---|---|---|---|---|---|
| Brazil | 515 | 614 | 1,394 | 1,312 | 1,402 | 987 | 848 | 767 | 949 |
| Canada | 1,311 | 1,191 | 1,263 | 990 | 804 | 873 | 968 | 983 | 1,059 |
| Germany | 766 | 9 | 6 | 8 | 6 | 5 | 5 | ||
| India | 388 | 2,694 | 849 | 460 | 509 | 567 | 567 | 579 | 457 |
| Mexico | 2,624 | 504 | 2,654 | 1,057 | 3,243 | 1,947 | 759 | 749 | 1,678 |
| Japan | 11 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| United States of America | 7,164 | 2,211 | 1,341 | 1,751 | 2,439 | 3,079 | 3,129 | 3,828 | 4,244 |
| Russian Federation | 3,626 | 6,750 | 7,861 | 8,385 | 8,635 | 8,853 | 5,755 | ||
| South Africa | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| China | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| United Kingdom | 807 | 0 | 1,083 | 1,106 | 787 | 618 | 563 | 586 | 573 |