STDEV using If(OR...)

Hello,

I need to calculate a standard deviation based on an If(OR) statement. Specifically, I have two columns, COMPANY and TAT. I need to calculate the standard deviation of TAT if COMPANY is equal to 1, 2, 5, or 12. I have tried using a statement like this: =STDEV(IF(OR(COMPANY="1", COMPANY="2", COMPANY="5", COMPANY="12"), TAT)), and it returns a number but it is not correct. Also, when I change the formula to calculate STDEV for other companies, i.e. =STDEV(IF(OR(COMPANY="3", COMPANY="4", COMPANY="6", COMPANY="11"), TAT)) I get the exact same value. Can anyone help??