| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.56 | 1.91 | 1.34 |
| 2024 | 1.51 | 1.76 | 1.28 |
| 2023 | 1.83 | 2.24 | 1.52 |
| 2022 | 1.77 | 2.95 | 1.42 |
| 2021 | 1.61 | 2.44 | 1.28 |
| 2020 | 1.52 | 2.57 | 1.31 |
| 2019 | 1.68 | 2.36 | 1.45 |
| 2018 | 2.01 | 2.4 | 1.53 |
| 2017 | 2.4 | 2.91 | 2.02 |
| 2016 | 3.44 | 5.9 | 2.75 |
| 2015 | 4.76 | 6.84 | 3.43 |
| 2014 | 3.55 | 4.31 | 2.63 |
| 2013 | 2.61 | 3.03 | 2.29 |
| 2012 | 3.36 | 4.04 | 2.02 |
| 2011 | 4.92 | 6.57 | 3.7 |
| 2010 | 6.76 | 8.14 | 4.81 |
| 2009 | 4.6 | 7.32 | 2.65 |
| 2008 | 4.2 | 7.02 | 1.85 |
| 2007 | 3.91 | 6.51 | 2.19 |
| 2006 | 1.97 | 2.52 | 1.61 |
| 2005 | 2.62 | 4.05 | 1.59 |
| 2004 | 4.26 | 5.16 | 2.95 |
| 2003 | 4.96 | 6.25 | 3.3 |