| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 3.18 | 3.43 | 2.97 |
| 2024 | 2.63 | 4.32 | 1.84 |
| 2023 | 2.25 | 3.51 | 1.55 |
| 2022 | 1.75 | 2.15 | 1.47 |
| 2021 | 2.43 | 2.85 | 2.06 |
| 2020 | 2.8 | 3.88 | 2.03 |
| 2019 | 3.14 | 4.68 | 2.38 |
| 2018 | 2.22 | 3.22 | 1.4 |
| 2017 | 3.17 | 3.69 | 2.61 |
| 2016 | 3.95 | 5.53 | 3.49 |
| 2015 | 5.11 | 8.05 | 2.93 |
| 2014 | 1.72 | 3.13 | 1.39 |
| 2013 | 1.66 | 2.25 | 1.23 |
| 2012 | 1.89 | 2.29 | 1.52 |
| 2011 | 2.46 | 3.32 | 1.75 |
| 2010 | 2.81 | 3.67 | 2.2 |
| 2009 | 4.1 | 5.16 | 3.16 |
| 2008 | 5.74 | 10.01 | 2.48 |
| 2007 | 7.58 | 11.64 | 3.25 |
| 2006 | 2.2 | 3.44 | 1.48 |
| 2005 | 2.18 | 3.1 | 1.36 |
| 2004 | 3.83 | 6 | 2.99 |
| 2003 | 3.48 | 4.05 | 2.73 |
| 2002 | 3.9 | 4.74 | 2.93 |
| 2001 | 6.34 | 10.96 | 2.86 |
| 2000 | 10.34 | 13.14 | 6.92 |
| 1999 | 5.86 | 8.43 | 3.58 |
| 1998 | 7.9 | 9.41 | 6.69 |
| 1997 | 8.15 | 11.14 | 6.62 |