| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.89 | 2.2 | 1.69 |
| 2024 | 1.96 | 2.76 | 1.58 |
| 2023 | 2.57 | 3.49 | 2.05 |
| 2022 | 3.28 | 4.61 | 2.11 |
| 2021 | 2.22 | 2.92 | 1.95 |
| 2020 | 2.27 | 3.04 | 2.02 |
| 2019 | 2.27 | 3.12 | 1.97 |
| 2018 | 2.43 | 3.09 | 1.85 |
| 2017 | 3.1 | 3.49 | 2.63 |
| 2016 | 5.71 | 7.03 | 3.36 |
| 2015 | 5.4 | 8.8 | 2.23 |
| 2014 | 2.03 | 2.57 | 1.71 |
| 2013 | 1.73 | 2.59 | 1.31 |
| 2012 | 1.81 | 2.39 | 1.46 |
| 2011 | 2.53 | 3.21 | 1.62 |
| 2010 | 2.25 | 3.36 | 1.6 |
| 2009 | 1.84 | 2.37 | 1.17 |
| 2008 | 2.05 | 4.09 | 0.92 |
| 2007 | 2.45 | 3.46 | 1.05 |
| 2006 | 1.01 | 1.15 | 0.77 |
| 2005 | 1.13 | 1.72 | 0.7 |
| 2004 | 2.18 | 2.89 | 1.46 |
| 2003 | 2.57 | 3.28 | 2.07 |
| 2002 | 3.91 | 4.02 | 3.76 |