Year	%
1977	8.3
1983	8.5
1987	8.7
1993	8.9
2004	8.6
2009	8.4
2011	8.2
2015	8.4
2016	8.4
2017	8.2
2018	8.1
2019	7.7
2020	7.7
2021	7.9