What do you mean by "files the most Trademark Issues"? If you are talking about domain disputes, the statistics are not in dispute:
http://www.wipo.int/amc/en/domains/statistics/countries.jsp?party=C
Complainant Country / Cases / Percent of Cases
United States of America 13022 36.32%
France 4133 11.53%
United Kingdom 2835 7.91%
Germany 2364 6.59%
Switzerland 1959 5.46%
Italy 1321 3.68%
Spain 1210 3.37%
Denmark 1114 3.11%
Netherlands 1009 2.81%
Sweden 782 2.18%
Australia 608 1.70%
Canada 566 1.58%
Brazil 510 1.42%
Turkey 458 1.28%
India 412 1.15%