Year % of cohort 1970 50.4904289245605 1978 86.1458511352539 1980 76.1189422607422 1983 89.641242980957 1984 90.6783599853516 1991 81.7214736938477 1992 85.863037109375 1993 88.2306594848633 1994 84.7961807250977 1995 91.0490188598633 1998 86.8567276000977 1999 85.5460433959961 2000 88.0519866943359 2001 86.1517868041992 2002 87.5480499267578 2003 87.5813522338867 2004 87.9032669067383 2005 88.8639297485352 2008 94.6768264770508 2012 95.3852233886719