
| 2024 | 0.09 | 0.12 | 1.07 | 78% |
| 2023 | 0.09 | 0.12 | 1.1 | 81.2% |
| 2022 | 0.1 | 0.11 | 1.07 | 88.8% |
| 2021 | 0.1 | 0.1 | 1.06 | 91.2% |
| 2020 | 0.09 | 0.09 | 0.97 | 98.6% |
| 2019 | 0.09 | 0.08 | 0.87 | 114% |
| 2018 | 0.09 | 0.09 | 0.95 | 104.1% |
| 2017 | 0.07 | 0.07 | 0.81 | 102.9% |
| 2016 | 0.07 | 0.07 | 0.79 | 111.4% |
| 2015 | 0.07 | 0.08 | 0.96 | 94.3% |
| 2014 | 0.07 | 0.11 | 1.38 | 67.1% |
| 2013 | 0.07 | 0.08 | 1.12 | 83.3% |
| 2012 | 0.07 | 0.07 | 0.9 | 104.4% |
| 2011 | 0.07 | 0.06 | 0.91 | 107.7% |
| 2010 | 0.07 | 0.06 | 0.81 | 128.3% |
| 2009 | 0.07 | 0.05 | 0.69 | 160.8% |
| 2008 | 0.07 | 0.05 | 0.76 | 138.8% |
| 2007 | 0.08 | 0.05 | 0.84 | 149.1% |
| 2006 | 0.08 | 0.05 | 0.84 | 151.1% |
| 2005 | 0.08 | 0.05 | 0.78 | 171.1% |
| 2004 | 0.08 | 0.04 | 0.71 | 202.5% |
| 2003 | 0.07 | 0.04 | 0.64 | 209% |
| 2002 | 0.07 | 0.03 | 0.61 | 214.3% |
| 2001 | 0.07 | 0.03 | 0.59 | 240.9% |
| 2000 | 0.07 | 0.03 | 0.64 | 215.9% |
| 1999 | 0.07 | 0.06 | 1.2 | 125.2% |
| 1998 | 0.07 | 0.06 | 1.17 | 129.3% |
| 1997 | 0.08 | 0.06 | 1.27 | 131.6% |
| 1996 | 0.08 | 0.06 | 1.34 | 136.3% |
| 1995 | 0.08 | 0.06 | 1.31 | 138.8% |
| 1994 | 0.07 | 0.06 | 1.3 | 128.7% |
| 1993 | 0.07 | 0.07 | 1.65 | 101.5% |
| 1992 | 0.07 | 0.07 | 1.72 | 106.9% |
| 1991 | 0.08 | 0.06 | 1.64 | 121.7% |
| 1990 | 0.08 | 0.07 | 1.84 | 125.2% |
| 1989 | 0.08 | 0.07 | 1.98 | 118.5% |
| 1988 | 0.08 | 0.07 | 2.08 | 116.7% |
| 1987 | 0.09 | 0.06 | 1.85 | 142% |
| 1986 | 0.09 | 0.07 | 2.05 | 128.8% |
| 1985 | 0.08 | 0.06 | 1.99 | 135.2% |
| 1984 | 0.08 | 0.06 | 2.08 | 124.9% |
| 1983 | 0.02 | 0.06 | 2.21 | 27.9% |
| 1982 | 0.02 | 0.06 | 2.25 | 26.8% |
| 1981 | 0.02 | 0.06 | 2.26 | 28.5% |
| 1980 | 0.02 | 0.06 | 2.26 | 29.7% |