| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.04 | 1.58 | 0.42 |
| 2024 | 1.2 | 2.14 | 0.5 |
| 2023 | 1.5 | 2.23 | 1.12 |
| 2022 | 1.55 | 1.83 | 1.02 |
| 2021 | 1.5 | 2.14 | 1.03 |
| 2020 | 2 | 2.8 | 1.37 |
| 2019 | 1.73 | 2.29 | 1.36 |
| 2018 | 1.75 | 2.23 | 1.3 |
| 2017 | 3.76 | 8.76 | 2.07 |
| 2016 | 5.39 | 7.08 | 3.41 |
| 2015 | 3.75 | 7.37 | 2.24 |
| 2014 | 2.32 | 4.03 | 1.59 |
| 2013 | 2.38 | 3.28 | 1.73 |
| 2012 | 2.63 | 3.67 | 1.91 |
| 2011 | 3.16 | 4.38 | 2.09 |
| 2010 | 2.85 | 3.59 | 2.21 |
| 2009 | 2.27 | 3.29 | 1.16 |
| 2008 | 1.89 | 3.29 | 0.92 |
| 2007 | 2.37 | 3.69 | 1.17 |
| 2006 | 1.23 | 1.6 | 1.01 |
| 2005 | 1.09 | 1.36 | 0.84 |
| 2004 | 1.92 | 2.93 | 1.34 |
| 2003 | 2.8 | 3.3 | 1.98 |
| 2002 | 5 | 6.35 | 2.9 |
| 2001 | 7.27 | 8.46 | 6.19 |
| 2000 | 6.24 | 7.51 | 4.56 |
| 1999 | 5.12 | 6.61 | 4.11 |
| 1998 | 4.66 | 5.98 | 3.64 |