| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 2 | 2.85 | 1.31 |
| 2024 | 0.97 | 1.77 | 0.71 |
| 2023 | 0.85 | 1.02 | 0.67 |
| 2022 | 0.73 | 0.99 | 0.55 |
| 2021 | 0.85 | 1.26 | 0.62 |
| 2020 | 0.65 | 0.75 | 0.59 |
| 2019 | 0.89 | 1.16 | 0.63 |
| 2018 | 1.45 | 2.31 | 0.9 |
| 2017 | 1.82 | 2.78 | 1.35 |
| 2016 | 1.33 | 1.6 | 0.96 |
| 2015 | 1.29 | 2.14 | 0.97 |
| 2014 | 0.68 | 1.25 | 0.55 |
| 2013 | 0.63 | 0.73 | 0.55 |
| 2012 | 0.6 | 0.67 | 0.51 |
| 2011 | 0.78 | 1.02 | 0.58 |
| 2010 | 0.96 | 1.37 | 0.76 |
| 2009 | 1.12 | 1.8 | 0.7 |
| 2008 | 1.62 | 3.95 | 0.54 |
| 2007 | 2.61 | 4.37 | 0.97 |
| 2006 | 0.79 | 0.9 | 0.68 |
| 2005 | 0.93 | 1.33 | 0.68 |
| 2004 | 1.61 | 2.53 | 0.98 |
| 2003 | 1.81 | 2.18 | 1.52 |
| 2002 | 1.75 | 1.94 | 1.58 |