| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.64 | 2.02 | 1.36 |
| 2024 | 1.06 | 1.97 | 0.84 |
| 2023 | 1.3 | 1.5 | 1.12 |
| 2022 | 1.51 | 2.52 | 1.04 |
| 2021 | 1.7 | 2.61 | 0.95 |
| 2020 | 0.69 | 1.17 | 0.43 |
| 2019 | 0.73 | 0.92 | 0.52 |
| 2018 | 0.82 | 1.2 | 0.48 |
| 2017 | 1.46 | 1.9 | 1.12 |
| 2016 | 1.37 | 1.68 | 1.18 |
| 2015 | 1.92 | 3.56 | 1.22 |
| 2014 | 1.27 | 1.83 | 0.98 |
| 2013 | 0.78 | 1.17 | 0.55 |
| 2012 | 0.63 | 0.78 | 0.51 |
| 2011 | 1.16 | 1.78 | 0.58 |
| 2010 | 1.14 | 1.45 | 0.78 |
| 2009 | 0.95 | 1.48 | 0.35 |
| 2008 | 0.54 | 0.9 | 0.25 |
| 2007 | 0.52 | 0.7 | 0.32 |
| 2006 | 0.4 | 0.62 | 0.31 |
| 2005 | 0.36 | 0.48 | 0.28 |
| 2004 | 0.61 | 1.18 | 0.37 |