Voter Turnout Statistics - Primary Elections Since 1974
| Year | No. Registered | No.Voted | % Turnout |
| 1974 | 162,876 | 84,585 | 51.9% |
| 1976 | 193,546 | 55,233 | 28.5% |
| 1978 | 224,118 | 108,057 | 48.2% |
| 1980 | 242,898 | 102,409 | 42.2% |
| 1982 | 241,357 | 139,133 | 57.6% |
| 1984 | 278,665 | 97,837 | 35.1% |
| 1986 | 280,351 | 150,768 | 53.8% |
| 1988 | 272,620 | 116,663 | 42.8% |
| 1990 | 283,827 | 134,111 | 47.2% |
| 1992 | 296,461 | 124,026 | 41.8% |
| 1994 | 325,260 | 116,214 | 35.7% |
| 1996 | 405,397 | 122,866 | 30.3% |
| 1998 | 446,200 | 109,906 | 24.6% |
| 2000 | 460,321 | 79,145 | 17.2% |
| 2002 | 453,248 | 115,340 | 25.5% |
| 2004 | 473,743 | 129,681 | 27.3% |
| 2006 | 464,838 | 160,217 | 34.4% |
| 2008 | 476,472 | 193,533 | 40.62% |
| 2010 | 487,456 | 164,047 | 33.65% |
| 2012 | 496,952 | 125,937 | 25.34% |
| 2014 | 494,900 | 193,097 | 39.02% |
| 2016 | 515,714 | 88,817 | 17.22% |
| 2018 | 566,790 | 115,727 | 20.42% |