CREATE TABLE table_203_330 (id NUMBER, "year of election" NUMBER, "candidates elected" NUMBER, "# of seats available" NUMBER, "# of votes" NUMBER, "% of popular vote" CLOB)

how many more seats were available in 1975 than 1963 ?
SELECT (SELECT "# of seats available" FROM table_203_330 WHERE "year of election" = 1975) - (SELECT "# of seats available" FROM table_203_330 WHERE "year of election" = 1963)
SELECT (SELECT "# of seats available" FROM "table_203_330" WHERE "year of election" = 1975) - (SELECT "# of seats available" FROM "table_203_330" WHERE "year of election" = 1963)