Meaningless on lots of levels. Many participants are just in it for the good work-out it gives them on the weekend. The organizers divide the categories by age, gender, and projected speed, putting the fast guys separate from us duffers. I my case, I was in a category of one, and only three guys in the whole race were older than me. Therefore, this is just a spreadsheet exercise for me and not to be taken seriously, except for the last stat.
In the Individual Time Trial, as posted by the organizers, there were 184 men and 34 women racing. I thought they capped it at 250, so cannot explain the discrepancy. Anyhow:
No one older than me finished faster
Against all men, I finished in the 43rd percentile
Against the Merckx (no aero equipment) men, I finished in the 77th percentile
Against aero men, I was in the 26th percentile.
Against the women my time was faster than 27 of the 34.
So, what does that tell me? Not much, especially since I projected an average speed of 21.5 mph and ended up at 19.2 mph. But, looking at my power output, I can see I only pushed hard once even though there are three steep climbs and several less steep but long ascents. Could I have pushed harder. Maybe.
To me, the most telling statistic was my heart-rate. I have a maximum HR of 165, which gives me a 90% reading of 148.5. For this race, my average HR was 148. True, my warm-up left a lot to be desired, but I spent 41 of 48 minutes right at my AT. Being able to hold that high a heart-rate for that long a time tells me my cardio health is very good. And that's why even though my main focus is cycling vacations, I train for and participate in races. Ride a bike, it's good for your health.