Where are you finding those ratings (times)? I've asked Trackmaster multiple times and they always state they only rate horses not racetracks.
It’s not published. You have to take a line in the program for a race at the track in question.
Take final time of that horse, look at the TM rating for that race for that horse, and then adjust by the variant located after the driver and medication (L).
Whatever number you come up with for that time, see what a rating of 100 will equate in time.
Example: Sat 6/8- race 1 Meadows, #3 Maloucious.
He got a TM rating of 84 based on his time of 151:2 on a -1 variant track.
(If possible, try to find a 0 variant track to calculate the figure).
-1 means the track was 1/5 second faster than normal.
So 151:2 becomes 151:3 to make the variant 0.
100-84 = 16 or 3 1/5 second
Subtract 3 1/5 second from 151:3 and the track is rated 148:2