| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 1.11 | 1.16 | 1.01 |
| 2024 | 1.03 | 1.34 | 0.8 |
| 2023 | 0.95 | 1.33 | 0.83 |
| 2022 | 1.07 | 1.49 | 0.87 |
| 2021 | 1.34 | 1.62 | 1.12 |
| 2020 | 1.24 | 2.33 | 0.97 |
| 2019 | 1.39 | 1.8 | 1.16 |
| 2018 | 1.59 | 2.19 | 1.13 |
| 2017 | 2.5 | 3.09 | 2.06 |
| 2016 | 2.29 | 2.86 | 1.92 |
| 2015 | 3 | 5.37 | 2 |
| 2014 | 1.52 | 2.38 | 1.21 |
| 2013 | 1.41 | 1.61 | 1.2 |
| 2012 | 1.53 | 2.03 | 1.21 |
| 2011 | 1.97 | 2.52 | 1.46 |
| 2010 | 2.64 | 3.24 | 1.97 |
| 2009 | 2.23 | 3.04 | 1.51 |
| 2008 | 3.14 | 5.79 | 1.27 |
| 2007 | 4.04 | 6.13 | 1.48 |
| 2006 | 1.48 | 1.72 | 1.26 |
| 2005 | 2.29 | 2.68 | 1.62 |
| 2004 | 3.03 | 4.18 | 2.44 |
| 2003 | 3.67 | 4.25 | 2.85 |
| 2002 | 4.47 | 5.56 | 3.26 |
| 2001 | 4.29 | 5.46 | 3.61 |
| 2000 | 5.4 | 6.75 | 2.89 |
| 1999 | 2.42 | 3.57 | 1.73 |
| 1998 | 3.51 | 4.55 | 2.65 |