| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2024 | 1.9 | 5.34 | 1.26 |
| 2023 | 1.5 | 2.32 | 0.92 |
| 2022 | 1 | 1.22 | 0.9 |
| 2021 | 0.99 | 1.24 | 0.86 |
| 2020 | 1.06 | 1.34 | 0.82 |
| 2019 | 1.05 | 1.5 | 0.83 |
| 2018 | 1.03 | 1.29 | 0.78 |
| 2017 | 1.39 | 1.65 | 1.2 |
| 2016 | 1.55 | 1.88 | 1.16 |
| 2015 | 2.37 | 4.81 | 1.57 |
| 2014 | 1.27 | 1.87 | 0.89 |
| 2013 | 0.77 | 1.2 | 0.59 |
| 2012 | 0.75 | 0.97 | 0.65 |
| 2011 | 1.14 | 1.38 | 0.74 |
| 2010 | 1.25 | 1.49 | 1.05 |
| 2009 | 1.03 | 1.35 | 0.7 |
| 2008 | 1.16 | 2.17 | 0.59 |
| 2007 | 1.68 | 2.45 | 0.94 |
| 2006 | 0.77 | 1 | 0.59 |
| 2005 | 0.8 | 1 | 0.55 |
| 2004 | 1.12 | 1.62 | 0.58 |
| 2003 | 1.18 | 1.34 | 1.09 |
| 2002 | 1.4 | 1.7 | 1.11 |
| 2001 | 1.66 | 2.15 | 1.21 |
| 2000 | 2.26 | 2.86 | 2.01 |
| 1999 | 2.99 | 4.51 | 2.19 |
| 1998 | 4.95 | 7.25 | 2.95 |
| 1997 | 7.94 | 11.59 | 3.71 |