Your Age should be your age at the time you ran the race.
The world records are taken from the AARS site: World Records as recognized by ARRS. They are as of June 2, 2017.
Yuu can enter any number of races, including only one, and your age can differ across races. .
These calculations use the 2017 age factors. The age range is 40 to 95. See 2017 Updated Age Factors. The calculations are using the estimated age factors for men. If women decline faster than men, then the age graded scores computed here are too low for women. In other words, they are biased against women. I have not attempted to estimate age factors for women in the running events because many of the times at the older ages appear soft, especially for the longer distances.