| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 3.17 | 4.61 | 2.45 |
| 2024 | 3.3 | 4.72 | 2.62 |
| 2023 | 2.93 | 4.26 | 2.02 |
| 2022 | 1.86 | 2.49 | 1.43 |
| 2021 | 1.86 | 2.51 | 1.32 |
| 2020 | 1.89 | 2.81 | 0.96 |
| 2019 | 1.52 | 2.16 | 1.11 |
| 2018 | 1.73 | 2.42 | 1.41 |
| 2017 | 2.71 | 3.58 | 2.16 |
| 2016 | 9.53 | 19.58 | 3.45 |
| 2015 | 10.41 | 17.67 | 5.29 |
| 2014 | 5.07 | 8.04 | 2.63 |
| 2013 | 2.3 | 3.41 | 1.77 |
| 2012 | 2.16 | 2.66 | 1.55 |
| 2011 | 5.9 | 9.37 | 2.12 |
| 2010 | 7.4 | 8.94 | 5.7 |
| 2009 | 6.52 | 9.85 | 2.99 |
| 2008 | 7.69 | 13.07 | 2.23 |
| 2007 | 7.9 | 11.79 | 3.33 |
| 2006 | 2.82 | 3.96 | 1.81 |
| 2005 | 1.78 | 2.23 | 1.36 |
| 2004 | 2.42 | 3.89 | 1.33 |
| 2003 | 3.59 | 4.32 | 2.63 |
| 2002 | 4.13 | 4.66 | 3.37 |
| 2001 | 5.68 | 7.26 | 4.03 |
| 2000 | 5.66 | 7.03 | 3.6 |
| 1999 | 4.49 | 5.85 | 3.55 |