| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0 | ||
| 2024 | 0 | ||
| 2023 | 0.53 | 0.89 | 0.33 |
| 2022 | 0.53 | 0.8 | 0.28 |
| 2021 | 0.71 | 0.99 | 0.35 |
| 2020 | 1.1 | 1.4 | 0.94 |
| 2019 | 1.17 | 1.62 | 0.97 |
| 2018 | 1.52 | 2.84 | 0.94 |
| 2017 | 1.84 | 2.5 | 1.6 |
| 2016 | 2.51 | 4.93 | 1.84 |
| 2015 | 4.47 | 8.09 | 2.72 |
| 2014 | 3.61 | 5.98 | 2.4 |
| 2013 | 4.96 | 6.24 | 3.56 |
| 2012 | 2.74 | 4.36 | 1.76 |
| 2011 | 2.79 | 4.48 | 1.64 |
| 2010 | 5.08 | 7.47 | 3.6 |
| 2009 | 5.58 | 7.67 | 2.54 |
| 2008 | 3.9 | 6.94 | 1.3 |
| 2007 | 4.92 | 7.05 | 2.88 |
| 2006 | 2.51 | 2.98 | 2.22 |
| 2005 | 2.89 | 4.05 | 2.14 |
| 2004 | 5.92 | 13.11 | 3.31 |
| 2003 | 10.14 | 12.92 | 3.42 |
| 2002 | 7.23 | 8.33 | 5 |
| 2001 | 9.81 | 12.13 | 7.18 |
| 2000 | 9.3 | 12.07 | 5.58 |
| 1999 | 6.27 | 8.86 | 4.24 |
| 1998 | 7.78 | 9.58 | 6.19 |
| 1997 | 6.73 | 8.88 | 4.89 |