| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 2.93 | 4.43 | 1.86 |
| 2024 | 1.75 | 2.75 | 1.32 |
| 2023 | 2.12 | 2.54 | 1.81 |
| 2022 | 1.86 | 2.37 | 1.4 |
| 2021 | 1.65 | 1.92 | 1.44 |
| 2020 | 2.2 | 2.59 | 1.68 |
| 2019 | 2.2 | 2.86 | 1.66 |
| 2018 | 2.42 | 3.46 | 1.56 |
| 2017 | 5.16 | 7.55 | 2.8 |
| 2016 | 6.4 | 8.55 | 4.52 |
| 2015 | 6.2 | 14.03 | 3.52 |
| 2014 | 3.27 | 4.19 | 2.31 |
| 2013 | 2.44 | 3.52 | 1.83 |
| 2012 | 2.1 | 2.65 | 1.56 |
| 2011 | 3.24 | 4.09 | 2.27 |
| 2010 | 3.68 | 4.62 | 3.07 |
| 2009 | 2.97 | 3.99 | 1.83 |
| 2008 | 4.08 | 8.12 | 1.51 |
| 2007 | 5.99 | 8.64 | 4.07 |
| 2006 | 2.47 | 4.07 | 1.76 |
| 2005 | 2.52 | 3.57 | 1.61 |
| 2004 | 4.93 | 8.24 | 2.62 |
| 2003 | 6.11 | 6.42 | 5.63 |
| 2002 | 5.8 | 6.37 | 4.12 |
| 2001 | 10.06 | 17.33 | 5.48 |
| 2000 | 11.64 | 14.04 | 6.51 |
| 1999 | 5.42 | 7.83 | 3.21 |
| 1998 | 4 | 5.9 | 2.7 |