| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.83 | 1.94 | 1.76 |
| 2024 | 1.91 | 2.28 | 1.49 |
| 2023 | 1.94 | 2.31 | 1.76 |
| 2022 | 1.91 | 2.26 | 1.68 |
| 2021 | 2.28 | 3 | 1.99 |
| 2020 | 2.69 | 3.25 | 2.32 |
| 2019 | 3.48 | 4.42 | 2.96 |
| 2018 | 3.88 | 5.15 | 2.86 |
| 2017 | 5.57 | 6.22 | 4.55 |
| 2016 | 5.98 | 7.85 | 5.27 |
| 2015 | 7.13 | 10.78 | 5.12 |
| 2014 | 3.19 | 6.46 | 2.4 |
| 2013 | 2.27 | 4.36 | 1.62 |
| 2012 | 1.94 | 2.29 | 1.6 |
| 2011 | 2.62 | 3.48 | 1.92 |
| 2010 | 3.75 | 5.1 | 2.92 |
| 2009 | 5.19 | 6.68 | 3.11 |
| 2008 | 4.14 | 7.02 | 2.28 |
| 2007 | 6.39 | 8.48 | 3.68 |
| 2006 | 2.35 | 3.85 | 1.82 |
| 2005 | 1.44 | 1.87 | 0.93 |
| 2004 | 2.42 | 3.76 | 1.59 |
| 2003 | 3.6 | 4.43 | 2.7 |
| 2002 | 4.97 | 5.65 | 3.63 |
| 2001 | 5.54 | 6.8 | 4.73 |
| 2000 | 5.41 | 6.24 | 4.8 |
| 1999 | 4.64 | 5.82 | 3.25 |
| 1998 | 4.82 | 6.17 | 3.61 |
| 1997 | 7.58 | 12.02 | 5.49 |