CREATE TABLE table_31978 ("Candidate" CLOB, "Party" CLOB, "Constituency" CLOB, "Year" CLOB, "Days" CLOB)

What year was Hazel Grove the constituent for the liberal party?
SELECT "Year" FROM table_31978 WHERE "Party" = 'liberal' AND "Constituency" = 'hazel grove'
SELECT "Year" FROM "table_31978" WHERE "Constituency" = 'hazel grove' AND "Party" = 'liberal'