{"year":"1971","percentage":5}
{"year":"1975","percentage":7.5}
{"year":"1979","percentage":10.5}
{"year":"1983","percentage":11}
{"year":"1987","percentage":14.5}
{"year":"1991","percentage":17.5}
{"year":"1995","percentage":21.5}
{"year":"1999","percentage":23.5}
{"year":"2003","percentage":26}
{"year":"2007","percentage":29.5}
{"year":"2011","percentage":29}
{"year":"2015","percentage":32}
{"year":"2019","percentage":42}