What is the code for the elevator in FNAF Sister Location?

I was playing Five Nights At Freddy's Sister Location when I found a little number pad in the elevator. I tried several number sequences (1983, 1987, 1234, 2320245) but none of them worked. If anyone knows the number sequence that'd be very useful to me.


I know I'm late, but if you type 1983 in the keypad to the left of the Baby poster you will turn on the monitors in the secret room permanently.