| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.95 | 2.56 | 1.62 |
| 2024 | 2.12 | 3.18 | 1.46 |
| 2023 | 2.22 | 3.07 | 1.62 |
| 2022 | 2.84 | 3.7 | 2.18 |
| 2021 | 3.09 | 5.23 | 1.8 |
| 2020 | 1.25 | 2.28 | 0.88 |
| 2019 | 1.35 | 1.8 | 1 |
| 2018 | 1.82 | 3.18 | 1.2 |
| 2017 | 2.7 | 4.49 | 1.71 |
| 2016 | 1.65 | 2.12 | 1.28 |
| 2015 | 1.71 | 2.86 | 1.1 |
| 2014 | 1.11 | 1.65 | 0.87 |
| 2013 | 1.52 | 2.13 | 1.11 |
| 2012 | 2.81 | 3.92 | 1.5 |
| 2011 | 5.22 | 6.73 | 2.86 |
| 2010 | 6.03 | 8.95 | 4.04 |
| 2009 | 5.58 | 8.72 | 2.35 |
| 2008 | 8.08 | 17.25 | 1.92 |
| 2007 | 9.9 | 20.03 | 3.29 |
| 2006 | 2.59 | 3.34 | 2.14 |
| 2005 | 2.28 | 2.94 | 1.7 |
| 2004 | 3.05 | 3.55 | 2.65 |
| 2003 | 2.61 | 3.06 | 2.38 |
| 2002 | 4.13 | 4.38 | 3.65 |
| 2001 | 4.65 | 6.05 | 3.34 |
| 2000 | 4.25 | 4.99 | 3.17 |