
| 2024 | 0.3 | 1.07 | 117 | 28.3% |
| 2023 | 0.28 | 1.09 | 119.2 | 26% |
| 2022 | 0.27 | 1.14 | 125.2 | 23.4% |
| 2021 | 0.28 | 1.2 | 134.2 | 23.3% |
| 2020 | 0.29 | 1.14 | 128 | 25% |
| 2019 | 0.29 | 1.25 | 140.2 | 23.6% |
| 2018 | 0.28 | 1.21 | 137.2 | 22.9% |
| 2017 | 0.29 | 1.24 | 140.4 | 23.7% |
| 2016 | 0.29 | 1.2 | 137.7 | 24.4% |
| 2015 | 0.29 | 1.19 | 137.2 | 24.4% |
| 2014 | 0.3 | 1.16 | 135.6 | 25.8% |
| 2013 | 0.3 | 1.2 | 142 | 24.8% |
| 2012 | 0.32 | 1.19 | 141.4 | 27% |
| 2011 | 0.29 | 1.2 | 143.3 | 23.9% |
| 2010 | 0.3 | 1.25 | 149.3 | 24.1% |
| 2009 | 0.31 | 1.19 | 142.1 | 26% |
| 2008 | 0.29 | 1.26 | 151.6 | 23.3% |
| 2007 | 0.3 | 1.26 | 152.3 | 23.9% |
| 2006 | 0.28 | 1.3 | 157.2 | 21.7% |
| 2005 | 0.26 | 1.3 | 158.5 | 20% |
| 2004 | 0.27 | 1.25 | 152.9 | 21.4% |
| 2003 | 0.27 | 1.22 | 150.4 | 21.9% |
| 2002 | 0.29 | 1.15 | 142.5 | 24.9% |
| 2001 | 0.28 | 1.14 | 142.3 | 24.5% |
| 2000 | 0.28 | 1.08 | 134.3 | 26.3% |
| 1999 | 0.27 | 1.09 | 136.9 | 25.1% |
| 1998 | 0.26 | 1.1 | 138.3 | 23.5% |
| 1997 | 0.25 | 1.09 | 136.2 | 23% |
| 1996 | 0.25 | 1.09 | 137.3 | 22.6% |
| 1995 | 0.26 | 1.02 | 128.1 | 25.7% |
| 1994 | 0.25 | 0.97 | 122.3 | 25.6% |
| 1993 | 0.26 | 0.97 | 122.5 | 27.3% |
| 1992 | 0.26 | 0.96 | 121.8 | 27.2% |
| 1991 | 0.25 | 1 | 129 | 25.1% |
| 1990 | 0.25 | 0.94 | 122.5 | 26.4% |
| 1989 | 0.26 | 0.88 | 115.4 | 29.6% |
| 1988 | 0.26 | 0.86 | 113.9 | 29.9% |
| 1987 | 0.22 | 0.84 | 111.4 | 26.6% |
| 1986 | 0.25 | 0.86 | 113.2 | 28.7% |
| 1985 | 0.25 | 0.88 | 116.2 | 28.3% |
| 1984 | 0.25 | 0.87 | 115 | 28.3% |
| 1983 | 0.19 | 0.83 | 109.8 | 23.4% |
| 1982 | 0.2 | 0.82 | 108.7 | 24.7% |
| 1981 | 0.2 | 0.87 | 115.6 | 23.2% |
| 1980 | 0.21 | 0.9 | 119 | 23.9% |