| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.82 | 2.46 | 1.46 |
| 2024 | 1.78 | 2.44 | 1.27 |
| 2023 | 4.48 | 6.8 | 2.23 |
| 2022 | 7.76 | 9.45 | 6.1 |
| 2021 | 6.25 | 9.5 | 3.84 |
| 2020 | 2.97 | 5.42 | 1.64 |
| 2019 | 1.63 | 2 | 1.2 |
| 2018 | 1.45 | 1.73 | 1.19 |
| 2017 | 1.95 | 2.38 | 1.6 |
| 2016 | 2.53 | 3.46 | 2.08 |
| 2015 | 3.19 | 5.28 | 1.98 |
| 2014 | 2.02 | 2.86 | 1.25 |
| 2013 | 1.3 | 1.52 | 1.03 |
| 2012 | 1.12 | 1.34 | 0.93 |
| 2011 | 1.67 | 2.16 | 1.07 |
| 2010 | 2.17 | 2.95 | 1.56 |
| 2009 | 1.63 | 2.61 | 0.82 |
| 2008 | 1.31 | 2.14 | 0.64 |
| 2007 | 1.72 | 2.5 | 0.96 |
| 2006 | 1.04 | 1.65 | 0.76 |
| 2005 | 0.8 | 1.08 | 0.61 |
| 2004 | 1.28 | 1.72 | 1.01 |
| 2003 | 1.62 | 1.96 | 1.22 |
| 2002 | 2.37 | 3.74 | 1.7 |
| 2001 | 4.25 | 5.22 | 3.14 |
| 2000 | 5.7 | 9.03 | 3.83 |
| 1999 | 4.21 | 7.31 | 3.13 |
| 1998 | 4.63 | 5.73 | 3.45 |