| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2026 | 1.52 | 1.62 | 1.34 |
| 2025 | 1.47 | 1.76 | 1.25 |
| 2024 | 1.33 | 1.89 | 1.09 |
| 2023 | 1.47 | 1.85 | 1.32 |
| 2022 | 1.47 | 1.95 | 1.24 |
| 2021 | 1.37 | 1.64 | 1.27 |
| 2020 | 1.54 | 1.87 | 1.32 |
| 2019 | 1.55 | 1.98 | 1.37 |
| 2018 | 1.66 | 2.07 | 1.33 |
| 2017 | 2.72 | 3.54 | 2 |
| 2016 | 3.54 | 4.59 | 2.87 |
| 2015 | 3.95 | 7.43 | 2.41 |
| 2014 | 2.56 | 3.19 | 2.08 |
| 2013 | 2.53 | 4.44 | 1.91 |
| 2012 | 2.97 | 3.79 | 2.2 |
| 2011 | 3.03 | 3.89 | 2.19 |
| 2010 | 2.73 | 3.33 | 2.13 |
| 2009 | 2.04 | 2.68 | 1.38 |
| 2008 | 1.77 | 2.98 | 1.07 |
| 2007 | 2.01 | 3.02 | 1.14 |
| 2006 | 1.15 | 1.38 | 0.88 |
| 2005 | 0.94 | 1.17 | 0.79 |
| 2004 | 1.43 | 1.89 | 1.09 |
| 2003 | 1.94 | 2.62 | 1.46 |
| 2002 | 2.89 | 3.27 | 2.32 |
| 2001 | 4.11 | 5.1 | 2.74 |
| 2000 | 13.7 | 18.23 | 7.33 |
| 1999 | 8.3 | 11.37 | 6.66 |
| 1998 | 7.92 | 9.94 | 6.12 |