Could Someone Explain This to Me Please (Days Since Last Race)

[Turbulator]

I'm reworking the CRC 4/28 races to look for mistakes, errors in judgment and oversights.

This horse (Almost Holy) won the 3rd at CRC, and with some fancy footwork I can sneak him into my top three and sniggle out a bet. (Hindsight handicapping I know)

However I'm confused about something. On the far right you see the days since last raced. Reading down the column from top to bottom it goes:

490
503
517
531
612
etc.

I don't get this. This horse is only six years old and he couldn't have had all that time off between those races, so what the heck am I overlooking? I must be reading this wrong.

Thanks,

Steve