| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 2.84 | 3.47 | 2.34 |
| 2024 | 1.49 | 4.68 | 0.87 |
| 2023 | 1.32 | 1.54 | 1.12 |
| 2022 | 1.55 | 2.54 | 1.18 |
| 2021 | 1.28 | 2.35 | 0.97 |
| 2020 | 1.16 | 1.51 | 1.04 |
| 2019 | 1.32 | 1.73 | 1.11 |
| 2018 | 1.37 | 1.75 | 1.11 |
| 2017 | 2.07 | 2.76 | 1.64 |
| 2016 | 2.93 | 3.89 | 2.01 |
| 2015 | 4.6 | 8.18 | 2.66 |
| 2014 | 2.75 | 3.89 | 1.94 |
| 2013 | 2.12 | 2.45 | 1.61 |
| 2012 | 2.44 | 3 | 1.78 |
| 2011 | 3.57 | 4.69 | 2.46 |
| 2010 | 4 | 5.48 | 3.06 |
| 2009 | 3.6 | 4.8 | 2.28 |
| 2008 | 4.47 | 9.34 | 1.98 |
| 2007 | 3.87 | 6.06 | 2.47 |
| 2006 | 2.81 | 5.4 | 1.74 |
| 2005 | 1.53 | 2.03 | 0.96 |
| 2004 | 2.31 | 2.87 | 1.82 |
| 2003 | 2.43 | 3.42 | 1.77 |
| 2002 | 3.38 | 3.69 | 2.65 |
| 2001 | 4.17 | 5.11 | 3.14 |
| 2000 | 3.95 | 5.02 | 2.59 |
| 1999 | 2.82 | 3.48 | 2.3 |