| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.63 | 1.97 | 1.43 |
| 2024 | 1.45 | 2 | 1.05 |
| 2023 | 2.1 | 2.75 | 1.73 |
| 2022 | 1.81 | 2.68 | 1.23 |
| 2021 | 1.71 | 2.75 | 1.14 |
| 2020 | 1.4 | 1.75 | 1.11 |
| 2019 | 1.62 | 2.45 | 1.19 |
| 2018 | 1.4 | 2 | 1.02 |
| 2017 | 2.76 | 3.59 | 1.85 |
| 2016 | 2.73 | 3.69 | 2.23 |
| 2015 | 3.61 | 6.13 | 2.19 |
| 2014 | 3.16 | 4.61 | 2.48 |
| 2013 | 2.3 | 3.12 | 1.79 |
| 2012 | 2.92 | 3.97 | 1.88 |
| 2011 | 6.1 | 8.68 | 3.86 |
| 2010 | 6.75 | 8.62 | 3.93 |
| 2009 | 3.29 | 4.39 | 1.86 |
| 2008 | 3.09 | 5.86 | 1.45 |
| 2007 | 4.72 | 6.53 | 2.85 |
| 2006 | 2.43 | 3.1 | 1.69 |
| 2005 | 1.84 | 2.17 | 1.4 |
| 2004 | 2.79 | 4.62 | 2.14 |
| 2003 | 4.1 | 5.71 | 2.56 |
| 2002 | 6.21 | 7.24 | 4.74 |
| 2001 | 7.43 | 8.62 | 5.74 |
| 2000 | 7.56 | 10.5 | 6.11 |
| 1999 | 6.71 | 8.24 | 5.14 |