Year	% of revenue
1995	22.471863535556615
1996	17.436225771783285
1997	23.68705888265182
1998	30.427059494541115
2002	16.585762010023767
2003	13.251789450601311
2004	10.224471668080328
2011	8.574659418260001
2012	8.018128470769282
2013	8.633290160771772
2014	8.113088640944829
2015	8.556785782858553
2016	9.918207856984123
2017	7.904479989155686
2018	7.27359398543174
2019	7.151084795482071
2020	6.447267896766054
2021	18.964889097011614