28% (1999)

38% (1997)

38% (1994)

49% (1990)

39% (1993)

50% (2000)

28% (1991)

55% (1996)

44% (1999)

45% (1993)

59% (1998)

51% (2001)

36% (2009)

46% (2007)

27% (2001)

55% (2009)

37% (1995)

45% (2005)

32% (1998)

58% (2014)