| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.96 | 2.53 | 1.52 |
| 2024 | 1.5 | 1.97 | 1.19 |
| 2023 | 1.75 | 2.21 | 1.32 |
| 2022 | 1.47 | 1.88 | 1.22 |
| 2021 | 1.91 | 2.6 | 1.65 |
| 2020 | 3.05 | 4.72 | 2.28 |
| 2019 | 3.24 | 3.84 | 2.78 |
| 2018 | 3.21 | 3.73 | 2.6 |
| 2017 | 3.76 | 5.03 | 3.04 |
| 2016 | 3.87 | 4.93 | 3.09 |
| 2015 | 4.08 | 6.43 | 2.7 |
| 2014 | 2.38 | 2.84 | 1.88 |
| 2013 | 2.85 | 3.83 | 2.03 |
| 2012 | 2.7 | 3.54 | 1.59 |
| 2011 | 3.83 | 5.42 | 2.82 |
| 2010 | 4.19 | 5.7 | 3.17 |
| 2009 | 2.88 | 3.92 | 1.76 |
| 2008 | 2.02 | 3.44 | 1.16 |
| 2007 | 2.3 | 3.36 | 1.34 |
| 2006 | 1.36 | 1.83 | 0.99 |
| 2005 | 1.31 | 1.82 | 0.94 |
| 2004 | 1.73 | 2.09 | 1.31 |
| 2003 | 1.94 | 2.43 | 1.44 |
| 2002 | 9.25 | 17.99 | 3.35 |