Year % (national estimate) 1960 19.32 1971 19.53 1978 19.93 1981 32.58 1986 33.09 1991 37.66 2001 44.89 2014 33.157 2017 35.457 2018 35.272 2019 31.503 2020 35.018 2021 31.795 2022 30.831