| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2026 | 2.02 | 2.56 | 1.65 |
| 2025 | 1.79 | 2.07 | 1.5 |
| 2024 | 1.52 | 2.12 | 1.23 |
| 2023 | 2.03 | 2.59 | 1.66 |
| 2022 | 2.1 | 3.3 | 1.56 |
| 2021 | 1.45 | 2.77 | 1.2 |
| 2020 | 1.58 | 2.05 | 1.31 |
| 2019 | 1.39 | 1.61 | 0.98 |
| 2018 | 1.31 | 1.7 | 1.05 |
| 2017 | 2.06 | 2.79 | 1.58 |
| 2016 | 2.68 | 3.44 | 2.26 |
| 2015 | 3.61 | 6.97 | 2.26 |
| 2014 | 3.92 | 7.14 | 3.08 |
| 2013 | 4.62 | 8.07 | 2.46 |
| 2012 | 3.17 | 4.31 | 2.48 |
| 2011 | 5.35 | 8.04 | 3.64 |
| 2010 | 8.2 | 9.9 | 6.92 |
| 2009 | 6.42 | 8.42 | 4.61 |
| 2008 | 7.04 | 14.57 | 3.69 |
| 2007 | 10.42 | 13.86 | 6.45 |
| 2006 | 5.13 | 7.27 | 3.3 |
| 2005 | 5.06 | 5.96 | 4.25 |
| 2004 | 9.08 | 18.77 | 4.45 |
| 2003 | 7.11 | 8.51 | 6.08 |
| 2002 | 10.21 | 11.72 | 9.05 |
| 2001 | 15.71 | 20.21 | 10.08 |
| 2000 | 13.64 | 16.12 | 10.43 |
| 1999 | 7.87 | 11.71 | 4 |
| 1998 | 5.2 | 6.44 | 3.69 |
| 1997 | 3.94 | 6 | 2.63 |