user: Question: What was the Score after 1991 in Category IVa?
Columns: ['Year', 'Category', 'Champions', 'Runners-up', 'Score']
Types: ['real', 'text', 'text', 'text', 'text']
Sample row: [1991.0, 'V', 'Laura Golarsa Magdalena Maleeva', 'Sandra Cecchini Laura Garrone', 'walkover']
SQL:

assistant: SELECT "Score" FROM "Table" WHERE "Year" > 1991.0 AND "Category" = 'IVa';