dickttx has a good question in post #39. Currently, percentages total 139.22%.
Because you can select multiple options. The percentages are percentage of respondents not percentage of total so if you have 5 respondents and 2 chose Lee, one Dillon, one RCBS and one Hornady and Dillon your percentages would show Lee 40%, Dillon 40%, RCBS, 20% and Hornady 20% for a total of 120%.