
| 2024 | 0.3 | 1.07 | 123.5 | 28.3% |
| 2023 | 0.28 | 1.09 | 125.8 | 26% |
| 2022 | 0.27 | 1.14 | 132.1 | 23.4% |
| 2021 | 0.28 | 1.2 | 141.6 | 23.3% |
| 2020 | 0.29 | 1.14 | 135.1 | 25% |
| 2019 | 0.29 | 1.25 | 147.9 | 23.6% |
| 2018 | 0.28 | 1.21 | 144.8 | 22.9% |
| 2017 | 0.29 | 1.24 | 148.1 | 23.7% |
| 2016 | 0.29 | 1.2 | 145.3 | 24.4% |
| 2015 | 0.29 | 1.19 | 144.7 | 24.4% |
| 2014 | 0.3 | 1.16 | 143.1 | 25.8% |
| 2013 | 0.3 | 1.2 | 149.8 | 24.8% |
| 2012 | 0.32 | 1.19 | 149.2 | 27% |
| 2011 | 0.29 | 1.2 | 151.1 | 23.9% |
| 2010 | 0.3 | 1.25 | 157.5 | 24.1% |
| 2009 | 0.31 | 1.19 | 149.9 | 26% |
| 2008 | 0.29 | 1.26 | 160 | 23.3% |
| 2007 | 0.3 | 1.26 | 160.7 | 23.9% |
| 2006 | 0.28 | 1.3 | 165.8 | 21.7% |
| 2005 | 0.26 | 1.3 | 167.3 | 20% |
| 2004 | 0.27 | 1.25 | 161.4 | 21.4% |
| 2003 | 0.27 | 1.22 | 158.7 | 21.9% |
| 2002 | 0.29 | 1.15 | 150.3 | 24.9% |
| 2001 | 0.28 | 1.14 | 150.1 | 24.5% |
| 2000 | 0.28 | 1.08 | 141.7 | 26.3% |
| 1999 | 0.27 | 1.09 | 144.4 | 25.1% |
| 1998 | 0.26 | 1.1 | 145.9 | 23.5% |
| 1997 | 0.25 | 1.09 | 143.7 | 23% |
| 1996 | 0.25 | 1.09 | 144.9 | 22.6% |
| 1995 | 0.26 | 1.02 | 135.2 | 25.7% |
| 1994 | 0.25 | 0.97 | 129 | 25.6% |
| 1993 | 0.26 | 0.97 | 129.3 | 27.3% |
| 1992 | 0.26 | 0.96 | 128.5 | 27.2% |
| 1991 | 0.25 | 1 | 136.1 | 25.1% |
| 1990 | 0.25 | 0.94 | 129.2 | 26.4% |
| 1989 | 0.26 | 0.88 | 121.7 | 29.6% |
| 1988 | 0.26 | 0.86 | 120.2 | 29.9% |
| 1987 | 0.22 | 0.84 | 117.5 | 26.6% |
| 1986 | 0.25 | 0.86 | 119.5 | 28.7% |
| 1985 | 0.25 | 0.88 | 122.6 | 28.3% |
| 1984 | 0.25 | 0.87 | 121.3 | 28.3% |
| 1983 | 0.19 | 0.83 | 115.9 | 23.4% |
| 1982 | 0.2 | 0.82 | 114.6 | 24.7% |
| 1981 | 0.2 | 0.87 | 122 | 23.2% |
| 1980 | 0.21 | 0.9 | 125.6 | 23.9% |