user: Question: Which Class has a Performance test of Minimum value, and a Usage of Semi Hepa, and a Performance of 99.5%?
Columns: ['Usage', 'Class', 'Performance', 'Performance test', 'Particulate size approaching 100% retention', 'Test Standard']
Types: ['text', 'text', 'text', 'text', 'text', 'text']
Sample row: ['Primary filters', 'G1', '65%', 'Average value', '>5µm', 'BS EN779']
SQL:

assistant: SELECT "Class" FROM "Table" WHERE "Performance test" = 'Minimum value' AND "Usage" = 'Semi Hepa' AND "Performance" = '99.5%';