| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2026 | 0 | ||
| 2025 | 0 | ||
| 2024 | 1.12 | 1.79 | 0.53 |
| 2023 | 1.63 | 1.92 | 1.36 |
| 2022 | 1.62 | 1.93 | 1.39 |
| 2021 | 1.46 | 2.08 | 1.05 |
| 2020 | 1.22 | 1.88 | 1.01 |
| 2019 | 1.17 | 1.91 | 0.95 |
| 2018 | 1.35 | 2.39 | 0.87 |
| 2017 | 2.75 | 4.05 | 2.18 |
| 2016 | 2.72 | 5.64 | 1.73 |
| 2015 | 3.31 | 6.59 | 1.8 |
| 2014 | 1.36 | 2.15 | 1.07 |
| 2013 | 1.3 | 1.61 | 1.08 |
| 2012 | 1.39 | 1.76 | 1.05 |
| 2011 | 2.37 | 3.27 | 1.14 |
| 2010 | 2.51 | 3.35 | 1.92 |
| 2009 | 1.65 | 2.06 | 0.97 |
| 2008 | 1.42 | 2.39 | 0.73 |
| 2007 | 1.84 | 2.6 | 0.89 |
| 2006 | 0.91 | 1.16 | 0.74 |
| 2005 | 0.8 | 1.03 | 0.66 |
| 2004 | 1.27 | 1.77 | 0.89 |
| 2003 | 1.62 | 2.08 | 1.26 |
| 2002 | 2.37 | 2.69 | 2.12 |