| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.96 | 2.3 | 1.57 |
| 2024 | 1.76 | 2.57 | 1.26 |
| 2023 | 2.42 | 2.93 | 1.91 |
| 2022 | 3.56 | 5.33 | 2.41 |
| 2021 | 2.5 | 4.79 | 1.38 |
| 2020 | 1.66 | 1.96 | 1.5 |
| 2019 | 1.84 | 2.24 | 1.52 |
| 2018 | 2.25 | 3.02 | 1.66 |
| 2017 | 3.27 | 4.21 | 2.58 |
| 2016 | 3.47 | 5.16 | 1.97 |
| 2015 | 3.01 | 4.91 | 1.78 |
| 2014 | 2.3 | 2.89 | 1.88 |
| 2013 | 2.38 | 3.11 | 2 |
| 2012 | 2.96 | 4.02 | 1.85 |
| 2011 | 4.95 | 7.07 | 2.89 |
| 2010 | 3.33 | 6.58 | 1.9 |
| 2009 | 2.36 | 3.07 | 1.24 |
| 2008 | 2.47 | 5.01 | 1.02 |
| 2007 | 3.53 | 6.15 | 1.37 |
| 2006 | 1.59 | 2.2 | 1.3 |
| 2005 | 2.08 | 2.65 | 1.28 |
| 2004 | 3.28 | 5.07 | 2.11 |
| 2003 | 4.08 | 4.99 | 3.17 |
| 2002 | 5.64 | 6.06 | 4.63 |