| 序号 | 时间 (年) |
数据 (亿美元) |
|---|---|---|
| 1 | 2021 | |
| 2 | 2020 | |
| 3 | 2019 | |
| 4 | 2018 | |
| 5 | 2017 | |
| 6 | 2016 | |
| 7 | 2015 | 1.89 |
| 8 | 2014 | 2.18 |
| 9 | 2013 | 1.65 |
| 10 | 2012 | 1.22 |
| 11 | 2011 | 1.96 |
| 12 | 2010 | 2.23 |
| 13 | 2009 | 1.24 |
| 14 | 2008 | 0.74 |
| 15 | 2007 | 0.41 |
| 16 | 2006 | 0.20 |
