| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0 | ||
| 2024 | 1.17 | 1.86 | 0.34 |
| 2023 | 2 | 2.4 | 1.61 |
| 2022 | 2.58 | 3.59 | 2.09 |
| 2021 | 2.03 | 2.77 | 1.81 |
| 2020 | 2.24 | 2.89 | 1.56 |
| 2019 | 2.03 | 2.85 | 1.67 |
| 2018 | 2.1 | 2.75 | 1.59 |
| 2017 | 3.35 | 4.12 | 2.64 |
| 2016 | 4.26 | 5.33 | 3.79 |
| 2015 | 6.41 | 14.12 | 3.83 |
| 2014 | 3.63 | 4.7 | 2.64 |
| 2013 | 2.5 | 3.07 | 1.57 |
| 2012 | 1.91 | 2.35 | 1.59 |
| 2011 | 2.92 | 3.73 | 1.74 |
| 2010 | 3.74 | 4.6 | 3.04 |
| 2009 | 3.61 | 4.35 | 2.58 |
| 2008 | 3.98 | 6.28 | 1.96 |
| 2007 | 3.62 | 5.52 | 1.59 |
| 2006 | 1.59 | 2.73 | 0.85 |
| 2005 | 0.94 | 1.4 | 0.65 |
| 2004 | 1.76 | 2.89 | 0.84 |
| 2003 | 1.99 | 2.45 | 1.59 |
| 2002 | 2.62 | 3 | 2.29 |
| 2001 | 3.65 | 4.45 | 2.66 |
| 2000 | 4.37 | 4.94 | 3.16 |