Interesting numbers, but hard to find any evidence that "the sport" is growing. For that matter, looks like you are just trying to measure the growth of OMA, against the decline of others. OMA is certainly growing, and and I congratulate you. I disagree with any analysis that these numbers indicate there were more racers in Ohio than the year before. Maybe there were, but the answer cannot be found here.
If you want to claim that "the sport" has changed trajectory, you are going to need total number of racers at all events, and compare that number to the prior year.
I find it especially interesting that we are going to measure the success of OMA Faircross by comparing it to CRA Faircross instead of measuring each event against its prior year's numbers. Is Medina Fair a great growing success because it has more riders than the fair in Cadiz? I guess getting finished before dark does cut down on the lighting costs, but if you want to come up with ideas to improve OMA and grow the sport, it is foolish to overlook the events that used to bring in more once a year, non-series, hometown riders, and had more exposure to the non-racing public than any others. All the places potentially new racers come from. First you have to look at the actual numbers before claiming that OMA takeover has been good for Faircross.