CREATE TABLE table_31151 ("Name/ designation" CLOB, "Year of intro" FLOAT, "Country of origin" CLOB, "Primary cartridge" CLOB, "Major users" CLOB)

How many years of introduction does the Neal Submachine Gun have?
SELECT COUNT("Year of intro") FROM table_31151 WHERE "Name/ designation" = 'Neal submachine gun'
SELECT COUNT("Year of intro") FROM "table_31151" WHERE "Name/ designation" = 'Neal submachine gun'