How old an oven is doesn't always mean anything - my apartments replaced our gas stoves with electric ones and my brand new oven was off over 50°!
Here is my test:
Put the oven rack in the center position and put the oven thermometer in the center of it. Then turn the oven on starting at 250°F, let it heat up until the light goes out (showing it thinks it is up to the temp you set it for) and then check the temp - be sure to write this down. Then, repeat in 50°F increments up to 500°F. You now know what the actual temp is for each setting from 250°-500°. Sometimes it will be off the same about all across the board, sometimes it's off more at one end of the scale than at the other.
Then, if it is off enough to complain to the apartment management about, you have the numbers to back up your claim that it needs to be re-calibrated or repaired.
"It ain't what you don't know that gets you in trouble. It's what you know for sure that just ain't so." - Mark Twain