| 时间 | 平均 | 最高 | 最低 |
|---|---|---|---|
| 2025 | 0.49 | 0.57 | 0.43 |
| 2024 | 0.49 | 0.57 | 0.4 |
| 2023 | 0.54 | 0.65 | 0.45 |
| 2022 | 0.51 | 0.76 | 0.34 |
| 2021 | 0.59 | 0.74 | 0.48 |
| 2020 | 0.47 | 0.91 | 0.36 |
| 2019 | 0.35 | 0.46 | 0.28 |
| 2018 | 0.59 | 0.76 | 0.3 |
| 2017 | 0.98 | 1.22 | 0.65 |
| 2016 | 1.43 | 2.13 | 1.09 |
| 2015 | 2.51 | 3.73 | 1.46 |
| 2014 | 2.82 | 3.38 | 2.49 |
| 2013 | 2.37 | 3.47 | 1.19 |
| 2012 | 0.81 | 1.11 | 0.68 |
| 2011 | 0.92 | 1.54 | 0.55 |
| 2010 | 1.38 | 1.95 | 0.93 |
| 2009 | 1.1 | 2.05 | 0.44 |
| 2008 | 0.93 | 2.27 | 0.41 |
| 2007 | 2 | 2.58 | 1.5 |
| 2006 | 0.99 | 1.49 | 0.57 |
| 2005 | 0.3 | 0.61 | 0.14 |
| 2004 | 0.56 | 1.2 | 0.22 |
| 2003 | 0.92 | 1.18 | 0.7 |
| 2002 | 0.56 | 0.66 | 0.39 |
| 2001 | 0.6 | 0.97 | 0.29 |
| 2000 | 0.19 | 0.34 | 0.07 |
| 1999 | 0.08 | 0.14 | 0.04 |
| 1998 | 0.19 | 0.33 | 0.05 |
| 1997 | 0.53 | 0.86 | 0.26 |