| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.7 | 2.61 | 1.35 |
| 2024 | 1.4 | 2.28 | 1.08 |
| 2023 | 1.59 | 1.89 | 1.43 |
| 2022 | 1.58 | 1.89 | 1.29 |
| 2021 | 1.66 | 2.64 | 1.25 |
| 2020 | 1.34 | 2.8 | 1.08 |
| 2019 | 1.65 | 1.91 | 1.47 |
| 2018 | 1.73 | 2.48 | 1.36 |
| 2017 | 2.37 | 3.19 | 1.82 |
| 2016 | 2.71 | 3.93 | 1.66 |
| 2015 | 2.54 | 3.8 | 1.6 |
| 2014 | 2.12 | 2.45 | 1.88 |
| 2013 | 2.55 | 3.56 | 2.09 |
| 2012 | 2.48 | 2.9 | 2.14 |
| 2011 | 3.48 | 4.46 | 2.21 |
| 2010 | 3.72 | 5.01 | 2.58 |
| 2009 | 2.79 | 4.81 | 1.81 |
| 2008 | 3.01 | 5.16 | 1.38 |
| 2007 | 3.18 | 4.45 | 1.76 |
| 2006 | 2.01 | 2.6 | 1.73 |
| 2005 | 2.07 | 2.95 | 1.34 |
| 2004 | 3.72 | 4.71 | 3.05 |
| 2003 | 3.89 | 4.46 | 3.06 |
| 2002 | 5.91 | 6.84 | 3.74 |
| 2001 | 5.95 | 6.81 | 4.88 |