Question: What is the average year with Alfredo Salazar Fina Salazar in mixed doubles?
SQL: SELECT AVG("Year") FROM "2-12218968-1" WHERE "Mixed doubles" = 'Alfredo Salazar Fina Salazar';

Question: Which women's doubles happened after 1987 and a women's single of Astrid van der Knaap?
SQL: SELECT "Women's doubles" FROM "2-12218968-1" WHERE "Year" > 1987.0 AND "Women's singles" = 'Astrid van der Knaap';