✳点击上方数值可查看历史数据
| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2018 | 12.74 | 16.16 | 10.68 |
| 2017 | 10.24 | 16.1 | 7.22 |
| 2016 | 9.65 | 10.85 | 8.48 |
| 2015 | 12.42 | 15.71 | 8.47 |
| 2014 | 8.67 | 16.32 | 7.26 |
| 2013 | 11.12 | 14.84 | 9.02 |
| 2012 | 16.10 | 18.26 | 13.36 |
| 2011 | 17.89 | 22.34 | 13.65 |
| 2010 | 22.18 | 29.58 | 18.93 |
| 2009 | 24.88 | 33.83 | 14.6 |
| 2008 | 551.05 | 1217.04 | 230.56 |
| 2007 | 42.54 | 70.59 | 21.61 |