Year	% gross
1999	1.39012002944946
2000	1.58635997772217
2001	1.38704001903534
2002	3.43290996551514
2003	4.14111995697021
2004	5.6029200553894
2005	7.11931991577148
2006	8.20090007781982
2007	9.36305046081543
2008	11.6162996292114
2009	14.5644397735596
2010	17.2066402435303
2011	19.6212100982666
2012	19.3967304229736
2013	21.2792301177979
2014	21.7901191711426
2015	20.5760192871094
2016	21.0570201873779
2017	21.1641502380371
2018	20.2174491882324