| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 2.26 | 2.48 | 2.01 |
| 2024 | 1.74 | 2.29 | 1.1 |
| 2023 | 2.13 | 2.85 | 1.86 |
| 2022 | 2.28 | 3.59 | 1.92 |
| 2021 | 1.91 | 2.21 | 1.76 |
| 2020 | 1.98 | 3.37 | 1.62 |
| 2019 | 2.13 | 2.91 | 1.79 |
| 2018 | 2.25 | 2.89 | 1.69 |
| 2017 | 2.46 | 3.09 | 2.09 |
| 2016 | 2.78 | 3.37 | 2.39 |
| 2015 | 3.87 | 7.22 | 1.68 |
| 2014 | 2.85 | 4.96 | 2.27 |
| 2013 | 2.49 | 2.82 | 2.16 |
| 2012 | 2.75 | 3.34 | 2.07 |
| 2011 | 3.91 | 5.41 | 2.69 |
| 2010 | 3.17 | 4.26 | 2.25 |
| 2009 | 2.9 | 4.07 | 1.58 |
| 2008 | 2.81 | 6.29 | 1.17 |
| 2007 | 3.45 | 5.35 | 1.5 |
| 2006 | 1.61 | 1.97 | 1.12 |
| 2005 | 1.15 | 1.41 | 0.98 |
| 2004 | 1.96 | 2.86 | 1.32 |
| 2003 | 2.73 | 3.38 | 2.03 |
| 2002 | 3.63 | 4.08 | 2.73 |
| 2001 | 4.44 | 5.34 | 3.32 |