| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.22 | 1.4 | 1.08 |
| 2024 | 1.19 | 1.62 | 0.88 |
| 2023 | 1.45 | 2.43 | 0.9 |
| 2022 | 0.97 | 1.24 | 0.76 |
| 2021 | 1.21 | 1.49 | 1.01 |
| 2020 | 1.68 | 2.53 | 1.18 |
| 2019 | 1.48 | 2.17 | 1.06 |
| 2018 | 1.23 | 1.66 | 0.82 |
| 2017 | 1.44 | 1.84 | 1.19 |
| 2016 | 2.86 | 4.38 | 1.73 |
| 2015 | 3.78 | 6.97 | 2.22 |
| 2014 | 1.84 | 3.3 | 1.4 |
| 2013 | 1.55 | 1.89 | 1.3 |
| 2012 | 1.85 | 2.39 | 1.42 |
| 2011 | 2.94 | 4.07 | 1.85 |
| 2010 | 3.19 | 4.74 | 1.94 |
| 2009 | 2.41 | 4.02 | 1.3 |
| 2008 | 2.53 | 5.07 | 1.06 |
| 2007 | 3.55 | 5.69 | 1.91 |
| 2006 | 1.63 | 2.22 | 1.12 |
| 2005 | 1.57 | 2.12 | 1.12 |
| 2004 | 2.52 | 3.47 | 1.94 |
| 2003 | 3.36 | 3.88 | 2.81 |
| 2002 | 4.92 | 5.66 | 4.31 |
| 2001 | 6.84 | 8.13 | 5.08 |
| 2000 | 7.61 | 9.91 | 6.56 |