| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2024 | 0.94 | 1.28 | 0.71 |
| 2023 | 1.1 | 1.34 | 0.91 |
| 2022 | 1.75 | 2.45 | 1.12 |
| 2021 | 2.23 | 3.4 | 1.64 |
| 2020 | 1.38 | 2.68 | 0.91 |
| 2019 | 1.43 | 1.8 | 1.1 |
| 2018 | 2.37 | 3.74 | 1.11 |
| 2017 | 2.76 | 3.76 | 2.2 |
| 2016 | 2.77 | 3.51 | 2.19 |
| 2015 | 4.17 | 7.54 | 2.35 |
| 2014 | 2.24 | 3.65 | 1.36 |
| 2013 | 2.83 | 6.3 | 1.35 |
| 2012 | 3.58 | 4.63 | 2.86 |
| 2011 | 5.92 | 24.46 | 3.02 |
| 2010 | 24.69 | 88.34 | 6.73 |
| 2009 | 37.93 | 71.76 | 19.2 |
| 2008 | 48.24 | 183.82 | 10 |
| 2007 | 148.63 | 212.02 | 120.36 |
| 2006 | 3.16 | 3.97 | 1.92 |
| 2005 | 3.59 | 4.8 | 2.45 |
| 2004 | 5.6 | 7.48 | 4.28 |
| 2003 | 8.41 | 12.33 | 5.29 |
| 2002 | 17.47 | 26.39 | 13.8 |
| 2001 | 30.28 | 36.73 | 22.26 |
| 2000 | 23.42 | 31.71 | 15.93 |
| 1999 | 11.38 | 13.65 | 9.22 |
| 1998 | 10.14 | 17.98 | 5.92 |
| 1997 | 5.68 | 10.51 | 3.58 |