Year	% gross
1979	8.51243019104004
1980	12.8183002471924
1981	12.5052795410156
2006	21.0205192565918
2007	17.9472503662109
2008	20.9970703125
2009	23.072359085083
2010	24.7170906066895
2011	25.613410949707
2012	26.0948905944824
2013	23.4598598480225
2014	24.8249492645264
2015	19.7099494934082
2017	17.0198707580566
2018	19.0071792602539
2023	13.7378396987915