| 1990 | 2000 | 2005 | |
|---|---|---|---|
| Spain | 3.5 | 8.4 | 9.6 |
| Russian Federation | 4.4 | 5.2 | 6.3 |
| Slovakia | 0.1 | 0.0 | 0.1 |
| Japan | 13.3 | 19.7 | 21.6 |
| Belarus | 5.6 | 0.2 | 0.2 |
| France | 9.0 | 14.4 | 16.0 |
| Canada | 7.1 | 10.2 | 10.2 |
| Romania | 0.2 | 0.3 | 0.4 |
| Norway | 0.6 | 0.9 | 1.1 |
| United States of America | 47.0 | 59.4 | 58.1 |
| Hungary | 0.5 | 0.7 | 0.7 |
| Bulgaria | 0.9 | 0.3 | 0.5 |
| Denmark | 1.8 | 2.4 | 2.6 |
| Finland | 1.0 | 1.1 | 1.3 |
| Germany | 11.5 | 19.5 | 23.3 |
| Turkey | 0.0 | 0.0 | 0.0 |
| Italy | 4.2 | 8.1 | 9.2 |
| Portugal | 1.5 | 2.0 | 2.3 |
| Czech Republic | 0.6 | 0.6 | 1.1 |
| Estonia | 0.1 | 0.1 | 0.1 |
| United Kingdom | 15.8 | 30.5 | 35.5 |
| Iceland | 0.2 | 0.4 | 0.4 |
| Ireland | 1.1 | 1.8 | 2.5 |
| Greece | 2.5 | 2.5 | 2.4 |
| Poland | 0.6 | 1.1 | 0.9 |
| Australia | 4.4 | 7.4 | 8.3 |
| Latvia | 0.2 | 0.1 | 0.2 |
| Netherlands | 4.6 | 9.8 | 10.9 |
| Ukraine | 2.4 | 0.4 | 0.6 |
| Luxembourg | 0.4 | 1.0 | 1.3 |
| Belgium | 3.1 | 4.7 | 3.5 |
| Switzerland | 3.1 | 4.7 | 3.5 |
| Austria | 0.9 | 1.7 | 2.0 |
| Croatia | 0.3 | 0.2 | 0.2 |
| Sweden | 1.4 | 2.0 | 2.0 |
| Slovenia | 0.1 | 0.1 | 0.1 |
| Lithuania | 0.4 | 0.1 | 0.1 |