user: Question: What was the round when there were 16 winners from the previous round?
Columns: ['Round', 'Clubs remaining', 'Clubs involved', 'Winners from previous round', 'New entries this round', 'Leagues entering at this round']
Types: ['text', 'real', 'real', 'text', 'text', 'text']
Sample row: ['Preliminary round', 123.0, 22.0, 'none', '22', 'Levels 4 and 5 in football league pyramid']
SQL:

assistant: SELECT "Round" FROM "Table" WHERE "Winners from previous round" = '16';