| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.73 | 2.14 | 1.5 |
| 2024 | 1.55 | 1.93 | 1.32 |
| 2023 | 1.89 | 2.39 | 1.5 |
| 2022 | 2.74 | 4.04 | 1.81 |
| 2021 | 4.41 | 6.9 | 3.28 |
| 2020 | 3.81 | 6.99 | 2.35 |
| 2019 | 2.63 | 3.31 | 2.22 |
| 2018 | 4.64 | 6.92 | 2.51 |
| 2017 | 5.07 | 6.9 | 3.97 |
| 2016 | 3.7 | 4.15 | 3.22 |
| 2015 | 4.9 | 7.27 | 3.74 |
| 2014 | 4.35 | 5.89 | 3.75 |
| 2013 | 3.7 | 5.3 | 2.98 |
| 2012 | 2.99 | 3.36 | 2.63 |
| 2011 | 4.21 | 5.89 | 2.73 |
| 2010 | 6.48 | 8.26 | 4.99 |
| 2009 | 5.12 | 7.05 | 3.42 |
| 2008 | 4.13 | 6.09 | 2.22 |
| 2007 | 3.99 | 6.02 | 1.95 |
| 2006 | 1.7 | 2.3 | 1.22 |
| 2005 | 1.47 | 2.01 | 0.9 |
| 2004 | 1.26 | 1.81 | 0.73 |