Year	Percent
1975	8.25
1976	7.85
1977	8.06
1978	8.7
1979	10.04
1980	7.67
1981	7.84
1982	6.55
1983	6.04
1991	4.7
2014	6.97
2017	9.32
2018	8.7
2019	6.92