Table schema:
CREATE TABLE table_name_91 (rank VARCHAR, annual_interchanges__millions__2011_12 VARCHAR, location VARCHAR, number_of_platforms VARCHAR)

Question: How many ranks are in liverpool with more than 3 platforms and an annual interchange less than 0.778 million?
SQL: SELECT COUNT(rank) FROM table_name_91 WHERE location = "liverpool" AND number_of_platforms > 3 AND annual_interchanges__millions__2011_12 < 0.778