| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.99 | 2.88 | 1.35 |
| 2024 | 1.93 | 2.6 | 1.41 |
| 2023 | 3.02 | 4.01 | 2.16 |
| 2022 | 2.19 | 3.83 | 0.93 |
| 2021 | 1.03 | 1.43 | 0.81 |
| 2020 | 1.1 | 1.53 | 0.78 |
| 2019 | 0.72 | 1.07 | 0.52 |
| 2018 | 0.79 | 1.33 | 0.58 |
| 2017 | 0.97 | 1.58 | 0.64 |
| 2016 | 1.18 | 1.52 | 1 |
| 2015 | 1.42 | 2.28 | 0.82 |
| 2014 | 0.87 | 1.21 | 0.6 |
| 2013 | 0.8 | 1.04 | 0.67 |
| 2012 | 0.81 | 1.09 | 0.63 |
| 2011 | 1.04 | 1.25 | 0.66 |
| 2010 | 1.56 | 2.46 | 1.02 |
| 2009 | 1.09 | 2.47 | 0.39 |
| 2008 | 1.23 | 2.87 | 0.31 |
| 2007 | 1.9 | 2.96 | 0.8 |
| 2006 | 0.8 | 1.1 | 0.62 |
| 2005 | 0.59 | 0.78 | 0.49 |
| 2004 | 1.06 | 2 | 0.54 |