| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.42 | 1.71 | 1.27 |
| 2024 | 1.08 | 2.57 | 0.76 |
| 2023 | 1.25 | 1.35 | 1.11 |
| 2022 | 1.23 | 1.69 | 1.03 |
| 2021 | 0.96 | 1.21 | 0.8 |
| 2020 | 1.2 | 1.65 | 0.96 |
| 2019 | 1.84 | 2.51 | 1.44 |
| 2018 | 2.36 | 3.93 | 1.41 |
| 2017 | 6.69 | 11.53 | 3.2 |
| 2016 | 5.17 | 8.1 | 3.98 |
| 2015 | 6.01 | 11.56 | 3.63 |
| 2014 | 14.83 | 32.41 | 5.49 |
| 2013 | 24.12 | 30.14 | 20.85 |
| 2012 | 23.38 | 28.91 | 18.86 |
| 2011 | 32.58 | 37.13 | 19.42 |
| 2010 | 33.96 | 39.16 | 26.66 |
| 2009 | 30.05 | 37.01 | 19.57 |
| 2008 | 41.29 | 112.64 | 13.15 |
| 2007 | 39.91 | 76.25 | 12.53 |
| 2006 | 8.28 | 13.5 | 4.85 |
| 2005 | 4.39 | 6.06 | 2.99 |
| 2004 | 5.81 | 9.93 | 3.38 |