SCHEMA:
CREATE TABLE table_24430894_20 (year VARCHAR, mutya_ng_pilipinas_asia_pacific VARCHAR)
USER:
List the number of years where ritchie ocampo was the mutya ng pilipinas winner.

QUERY:
SELECT COUNT(year) FROM table_24430894_20 WHERE mutya_ng_pilipinas_asia_pacific = "Ritchie Ocampo"