user: Question: How many reservations for sc/st are there in constituency 191?
Columns: ['Constituency No.', 'Vidhan Sabha Constituency', 'Reservation for SC/ST', 'District', 'Lok Sabha']
Types: ['real', 'text', 'text', 'text', 'text']
Sample row: [151.0, 'Parbatta (Vidhan Sabha constituency)', 'None', 'Khagaria', '25 Khagaria']
SQL:

assistant: SELECT COUNT("Reservation for SC/ST") FROM "Table" WHERE "Constituency No." = 191.0;