| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0.75 | 0.99 | 0.52 |
| 2024 | 0.57 | 0.86 | 0.43 |
| 2023 | 0.79 | 0.93 | 0.69 |
| 2022 | 0.87 | 1.3 | 0.71 |
| 2021 | 0.74 | 0.83 | 0.65 |
| 2020 | 0.89 | 1.1 | 0.75 |
| 2019 | 0.95 | 1.2 | 0.8 |
| 2018 | 1.03 | 1.41 | 0.78 |
| 2017 | 1.53 | 1.93 | 1.29 |
| 2016 | 1.47 | 2.15 | 1.2 |
| 2015 | 1.64 | 2.89 | 1.19 |
| 2014 | 1.01 | 1.46 | 0.85 |
| 2013 | 1.06 | 1.38 | 0.92 |
| 2012 | 1.2 | 1.58 | 0.95 |
| 2011 | 1.5 | 2.25 | 0.99 |
| 2010 | 2.17 | 2.63 | 1.84 |
| 2009 | 2.5 | 3.41 | 1.34 |
| 2008 | 3.19 | 7.04 | 1.05 |
| 2007 | 5.79 | 9.21 | 2.97 |
| 2006 | 3.48 | 5.21 | 2.35 |
| 2005 | 2.28 | 2.89 | 1.55 |
| 2004 | 2.95 | 3.86 | 2.26 |
| 2003 | 3.41 | 4.33 | 2.42 |