| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2026 | 2.84 | 3.26 | 2.14 |
| 2025 | 1.5 | 2.59 | 0.64 |
| 2024 | 1.02 | 1.64 | 0.69 |
| 2023 | 1.44 | 1.61 | 1.28 |
| 2022 | 1.8 | 2.64 | 1.35 |
| 2021 | 2.34 | 3.15 | 1.93 |
| 2020 | 2.45 | 3.51 | 1.64 |
| 2019 | 2.19 | 2.77 | 1.26 |
| 2018 | 2.61 | 3.93 | 1.27 |
| 2017 | 4.5 | 6.22 | 3.63 |
| 2016 | 5.28 | 6.51 | 4.19 |
| 2015 | 6.19 | 8.33 | 2.64 |
| 2014 | 2.43 | 3.39 | 1.84 |
| 2013 | 2.13 | 2.77 | 1.75 |
| 2012 | 1.76 | 2.04 | 1.48 |
| 2011 | 2.34 | 2.83 | 1.62 |
| 2010 | 2.93 | 4.03 | 2.29 |
| 2009 | 4.18 | 5.59 | 3.09 |
| 2008 | 5.44 | 7.5 | 4.2 |
| 2007 | 6.01 | 8.17 | 3.42 |
| 2006 | 3.04 | 3.54 | 2.26 |
| 2005 | 2.48 | 3.62 | 1.6 |
| 2004 | 3.96 | 4.63 | 3.3 |
| 2003 | 4.69 | 5.58 | 3.62 |
| 2002 | 5.34 | 6.23 | 3.7 |
| 2001 | 6.29 | 7.7 | 4.45 |
| 2000 | 7.42 | 11.29 | 5.2 |
| 1999 | 4.74 | 6.56 | 3.41 |
| 1998 | 7.18 | 9.35 | 4.85 |
| 1997 | 7.74 | 11.11 | 5.51 |