| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.78 | 2.18 | 1.48 |
| 2024 | 2.04 | 2.51 | 1.62 |
| 2023 | 2.12 | 2.67 | 1.66 |
| 2022 | 2.53 | 3.49 | 1.66 |
| 2021 | 4.11 | 5.92 | 2.47 |
| 2020 | 3.55 | 4.77 | 2.55 |
| 2019 | 2.29 | 3.21 | 1.65 |
| 2018 | 2.76 | 4.11 | 1.63 |
| 2017 | 2.75 | 4.04 | 2.12 |
| 2016 | 1.82 | 2.41 | 1.48 |
| 2015 | 3.16 | 3.69 | 2.16 |
| 2014 | 2.2 | 3.07 | 1.79 |
| 2013 | 2.87 | 3.45 | 2.41 |
| 2012 | 2.49 | 3.06 | 2 |
| 2011 | 3.11 | 3.84 | 2.16 |
| 2010 | 3.73 | 5.08 | 2.91 |
| 2009 | 3.38 | 4.89 | 1.43 |
| 2008 | 2.76 | 5.2 | 0.98 |
| 2007 | 3.66 | 5.23 | 1.75 |
| 2006 | 1.91 | 2.7 | 1.46 |
| 2005 | 1.54 | 1.94 | 1.06 |
| 2004 | 2.18 | 3.03 | 1.66 |
| 2003 | 2.83 | 3.24 | 2.27 |
| 2002 | 3.63 | 4.19 | 2.61 |
| 2001 | 3.82 | 4.74 | 2.84 |
| 2000 | 5.78 | 7.01 | 3.19 |
| 1999 | 3.5 | 4.45 | 2.26 |
| 1998 | 6.16 | 8.4 | 4.19 |