| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.32 | 1.57 | 1.14 |
| 2024 | 1.18 | 1.41 | 1.01 |
| 2023 | 1.49 | 1.82 | 1.25 |
| 2022 | 1.56 | 1.81 | 1.36 |
| 2021 | 1.79 | 2.48 | 1.56 |
| 2020 | 2.19 | 3.09 | 1.55 |
| 2019 | 2.1 | 2.86 | 1.72 |
| 2018 | 1.79 | 2.28 | 1.43 |
| 2017 | 2.69 | 3.45 | 2.1 |
| 2016 | 3.41 | 4.18 | 2.52 |
| 2015 | 4.23 | 6.03 | 2.75 |
| 2014 | 3.46 | 4.54 | 2.96 |
| 2013 | 3.44 | 5.11 | 2.59 |
| 2012 | 3.19 | 6.2 | 2.2 |
| 2011 | 5.05 | 6.01 | 3.67 |
| 2010 | 4.92 | 6.69 | 3.53 |
| 2009 | 3.47 | 5.33 | 1.95 |
| 2008 | 3.52 | 6.33 | 1.46 |
| 2007 | 4.88 | 6.7 | 2.7 |
| 2006 | 2.63 | 3.12 | 2.13 |
| 2005 | 3.27 | 4.84 | 2.11 |
| 2004 | 4.61 | 6.3 | 3.5 |
| 2003 | 4.3 | 5.21 | 2.7 |
| 2002 | 6.3 | 7.14 | 5.07 |
| 2001 | 6.23 | 7.21 | 4.57 |
| 2000 | 8.72 | 15.3 | 4.57 |
| 1999 | 3.19 | 4.54 | 2.36 |
| 1998 | 3.03 | 3.53 | 2.49 |