| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 2.2 | 2.53 | 1.9 |
| 2024 | 1.54 | 3.45 | 1.13 |
| 2023 | 1.7 | 1.87 | 1.54 |
| 2022 | 1.79 | 2.15 | 1.47 |
| 2021 | 1.81 | 2.31 | 1.53 |
| 2020 | 2 | 2.74 | 1.58 |
| 2019 | 1.8 | 2.43 | 1.39 |
| 2018 | 1.88 | 2.77 | 1.29 |
| 2017 | 3.4 | 4.26 | 2.6 |
| 2016 | 4.46 | 6.25 | 3.5 |
| 2015 | 4.43 | 7.85 | 2.73 |
| 2014 | 2.67 | 3.66 | 1.83 |
| 2013 | 1.95 | 2.36 | 1.62 |
| 2012 | 2.51 | 3.89 | 1.73 |
| 2011 | 5.73 | 7.85 | 2.85 |
| 2010 | 7.02 | 9.24 | 4.72 |
| 2009 | 3.62 | 5.83 | 1.36 |
| 2008 | 2.07 | 3.43 | 1.12 |
| 2007 | 2.62 | 4.27 | 1.01 |
| 2006 | 0.94 | 1.13 | 0.74 |
| 2005 | 0.98 | 1.27 | 0.77 |
| 2004 | 1.89 | 2.63 | 1.3 |
| 2003 | 2.7 | 3.36 | 2.11 |
| 2002 | 3.83 | 4.48 | 3.18 |
| 2001 | 5.15 | 6.13 | 3.83 |