| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2026 | 1.51 | 1.69 | 1.34 |
| 2025 | 1.67 | 1.88 | 1.54 |
| 2024 | 1.89 | 2.26 | 1.45 |
| 2023 | 2.82 | 3.61 | 2.2 |
| 2022 | 2.39 | 3.67 | 1.8 |
| 2021 | 4.29 | 7.21 | 2.82 |
| 2020 | 5.76 | 7.11 | 4.8 |
| 2019 | 4.39 | 5.68 | 2.28 |
| 2018 | 2.49 | 3.61 | 1.39 |
| 2017 | 1.69 | 1.98 | 1.51 |
| 2016 | 2.15 | 2.55 | 1.74 |
| 2015 | 2.3 | 3.24 | 1.54 |
| 2014 | 2.1 | 2.67 | 1.74 |
| 2013 | 2.08 | 2.54 | 1.54 |
| 2012 | 2.19 | 2.83 | 1.4 |
| 2011 | 2.88 | 3.9 | 2.1 |
| 2010 | 3.47 | 4.66 | 2.69 |
| 2009 | 2.65 | 3.47 | 2.13 |
| 2008 | 2.92 | 4.69 | 1.53 |
| 2007 | 3.49 | 5.52 | 2.05 |
| 2006 | 1.31 | 2.13 | 0.92 |
| 2005 | 1.12 | 1.34 | 0.84 |
| 2004 | 1.68 | 2.14 | 1.23 |
| 2003 | 2.2 | 2.7 | 1.91 |
| 2002 | 2.93 | 3.54 | 2.54 |
| 2001 | 4.4 | 5.37 | 3.03 |
| 2000 | 4.46 | 5.41 | 3.52 |
| 1999 | 4.53 | 5.7 | 3.54 |