| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 2.29 | 2.73 | 2.13 |
| 2024 | 2.43 | 3.6 | 1.93 |
| 2023 | 2.81 | 4.17 | 2.3 |
| 2022 | 2.57 | 3.17 | 2.1 |
| 2021 | 2.74 | 3.52 | 2.27 |
| 2020 | 3.19 | 4.15 | 2.24 |
| 2019 | 2.57 | 3.1 | 2.12 |
| 2018 | 2.52 | 3.12 | 1.85 |
| 2017 | 3.28 | 4.19 | 2.79 |
| 2016 | 6.03 | 13.12 | 3.61 |
| 2015 | 12.7 | 23.81 | 7.96 |
| 2014 | 8.72 | 11.24 | 7.13 |
| 2013 | 8.87 | 10.79 | 7.28 |
| 2012 | 10.57 | 14.28 | 7.04 |
| 2011 | 20.97 | 30.33 | 11.82 |
| 2010 | 16.87 | 28.41 | 9.82 |
| 2009 | 9.73 | 14.75 | 4.07 |
| 2008 | 7.08 | 13.55 | 3.03 |
| 2007 | 8.29 | 12.66 | 2.94 |
| 2006 | 2.82 | 4.17 | 1.6 |
| 2005 | 2 | 2.87 | 1.34 |
| 2004 | 3.41 | 5.26 | 1.53 |
| 2003 | 4.79 | 5.63 | 3.86 |
| 2002 | 5.65 | 5.89 | 5.5 |