| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2026 | 1.82 | 2.18 | 1.52 |
| 2025 | 1.25 | 2.03 | 0.9 |
| 2024 | 1.1 | 1.31 | 0.89 |
| 2023 | 1.58 | 2.43 | 1.18 |
| 2022 | 1.7 | 2.48 | 1.06 |
| 2021 | 2.18 | 3.14 | 1.76 |
| 2020 | 1 | 1.88 | 0.66 |
| 2019 | 0.86 | 1.08 | 0.75 |
| 2018 | 1.18 | 1.76 | 0.8 |
| 2017 | 2.01 | 2.41 | 1.63 |
| 2016 | 1.93 | 2.34 | 1.63 |
| 2015 | 2.26 | 4.13 | 1.47 |
| 2014 | 1.38 | 1.7 | 1.16 |
| 2013 | 1.67 | 2.28 | 1.35 |
| 2012 | 1.88 | 2.43 | 1.42 |
| 2011 | 3.06 | 4.2 | 1.88 |
| 2010 | 3.22 | 4.98 | 2.06 |
| 2009 | 4.46 | 6.12 | 1.77 |
| 2008 | 4.4 | 9.3 | 1.42 |
| 2007 | 5 | 9.24 | 1.76 |
| 2006 | 1.95 | 2.36 | 1.65 |
| 2005 | 2.16 | 2.78 | 1.44 |
| 2004 | 2.67 | 4.97 | 1.95 |