| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.41 | 1.62 | 1.28 |
| 2024 | 0.97 | 2.09 | 0.6 |
| 2023 | 0.86 | 1.08 | 0.72 |
| 2022 | 0.79 | 1.2 | 0.64 |
| 2021 | 0.89 | 1.11 | 0.72 |
| 2020 | 1.19 | 1.8 | 0.92 |
| 2019 | 1.24 | 1.62 | 1.04 |
| 2018 | 1.63 | 2.61 | 1.1 |
| 2017 | 2.49 | 3.11 | 2.05 |
| 2016 | 2.64 | 3.33 | 2.14 |
| 2015 | 3.44 | 6.05 | 2.02 |
| 2014 | 1.78 | 2.46 | 1.42 |
| 2013 | 1.81 | 2.32 | 1.47 |
| 2012 | 1.84 | 2.33 | 1.47 |
| 2011 | 2.26 | 2.92 | 1.49 |
| 2010 | 2.63 | 3.35 | 1.8 |
| 2009 | 3.03 | 4.27 | 1.53 |
| 2008 | 2.75 | 5.66 | 1.18 |
| 2007 | 4.74 | 7.53 | 2.29 |
| 2006 | 1.81 | 2.93 | 1.07 |
| 2005 | 1.08 | 1.39 | 0.82 |
| 2004 | 1.39 | 1.92 | 1.05 |
| 2003 | 1.5 | 1.96 | 1.21 |
| 2002 | 2.75 | 3.04 | 2.25 |
| 2001 | 3.36 | 3.89 | 2.62 |
| 2000 | 3.23 | 3.88 | 2.53 |
| 1999 | 2.76 | 4.15 | 2.21 |
| 1998 | 3.78 | 5.45 | 2.57 |
| 1997 | 5.47 | 9.66 | 3.06 |