| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.85 | 2.38 | 1.49 |
| 2024 | 1.72 | 2.36 | 1.18 |
| 2023 | 2.17 | 2.79 | 1.85 |
| 2022 | 2.41 | 3.06 | 1.76 |
| 2021 | 1.61 | 3.82 | 0.9 |
| 2020 | 1.17 | 2.13 | 0.89 |
| 2019 | 1.37 | 1.72 | 1.16 |
| 2018 | 1.6 | 2.14 | 1.19 |
| 2017 | 2.16 | 2.85 | 1.88 |
| 2016 | 1.52 | 2.36 | 1.21 |
| 2015 | 1.81 | 3.17 | 1.09 |
| 2014 | 0.89 | 1.28 | 0.72 |
| 2013 | 0.86 | 1 | 0.74 |
| 2012 | 0.89 | 1.05 | 0.78 |
| 2011 | 1.27 | 1.71 | 0.83 |
| 2010 | 1.16 | 1.45 | 0.89 |
| 2009 | 0.99 | 1.42 | 0.55 |
| 2008 | 0.92 | 1.93 | 0.46 |
| 2007 | 1.52 | 2.21 | 0.81 |
| 2006 | 0.8 | 1 | 0.58 |
| 2005 | 0.61 | 0.74 | 0.49 |
| 2004 | 1 | 1.36 | 0.67 |
| 2003 | 1.6 | 2.09 | 1.07 |
| 2002 | 2.36 | 2.67 | 2.01 |
| 2001 | 3.37 | 4.06 | 2.48 |
| 2000 | 3.45 | 3.84 | 3.15 |