| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 2.15 | 5.76 | 0.86 |
| 2024 | 1.15 | 1.66 | 0.56 |
| 2023 | 1.51 | 1.89 | 1.21 |
| 2022 | 1.31 | 1.75 | 0.99 |
| 2021 | 1.8 | 2.43 | 1.4 |
| 2020 | 1.99 | 2.99 | 1.3 |
| 2019 | 1.63 | 2.31 | 1.27 |
| 2018 | 1.45 | 1.92 | 0.93 |
| 2017 | 2.28 | 3.04 | 1.7 |
| 2016 | 2.93 | 3.67 | 2.2 |
| 2015 | 3.58 | 6.31 | 2.12 |
| 2014 | 2.97 | 4.18 | 2.21 |
| 2013 | 2.38 | 3.57 | 1.63 |
| 2012 | 2.35 | 3.13 | 1.78 |
| 2011 | 3.36 | 4.42 | 2.06 |
| 2010 | 4.77 | 8.86 | 2.78 |
| 2009 | 3.84 | 7.12 | 2.46 |
| 2008 | 3.77 | 7.73 | 1.64 |
| 2007 | 7.28 | 14.1 | 4.34 |
| 2006 | 5.97 | 9.31 | 3.84 |
| 2005 | 5.63 | 7.13 | 4.28 |
| 2004 | 6.88 | 12.06 | 4.22 |
| 2003 | 7.17 | 8.22 | 6.15 |
| 2002 | 4.56 | 5.9 | 2.59 |
| 2001 | 6.4 | 8.36 | 4.14 |
| 2000 | 5.55 | 6.85 | 3.72 |
| 1999 | 3.8 | 4.39 | 3.18 |