| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 2.23 | 2.57 | 1.76 |
| 2024 | 1.77 | 3.39 | 1.22 |
| 2023 | 1.83 | 2.05 | 1.65 |
| 2022 | 2.11 | 2.57 | 1.74 |
| 2021 | 2.49 | 3.75 | 1.84 |
| 2020 | 2.64 | 4.22 | 1.68 |
| 2019 | 1.87 | 2.36 | 1.48 |
| 2018 | 1.75 | 2.2 | 1.26 |
| 2017 | 3.38 | 6.23 | 2.08 |
| 2016 | 4.58 | 5.38 | 3.26 |
| 2015 | 5.07 | 9.11 | 3.24 |
| 2014 | 3.81 | 4.53 | 3.34 |
| 2013 | 3.53 | 4.62 | 2.42 |
| 2012 | 2.57 | 3.11 | 2.08 |
| 2011 | 4.23 | 5.69 | 2.44 |
| 2010 | 5.32 | 6.8 | 4.08 |
| 2009 | 4.72 | 5.85 | 3.16 |
| 2008 | 3.76 | 6.06 | 2.34 |
| 2007 | 2.88 | 4.35 | 1.04 |
| 2006 | 0.97 | 1.22 | 0.72 |
| 2005 | 1.09 | 1.42 | 0.79 |
| 2004 | 1.57 | 2.08 | 1.24 |
| 2003 | 2.02 | 2.49 | 1.45 |
| 2002 | 2.79 | 3.38 | 2.21 |
| 2001 | 8.83 | 11.01 | 3.94 |