If so, they maintain a national database of all of the classifers and all of the individual results for each of them. Basically the highest hit factors are looked at to determine the 100% (there is some process involved, but I forget). After that is established. your hit factor is compared to the 100% hit factor and expressed as a percentage.
If I might try to clarify a little. The hit factor is the "points per second" number that is calculated like during a match. The highest hit factors, in the nation, are averaged to arrive at the "high hit factor". Your hit factor is divided by the "high hit factor", and then multiplied by 100 to arrive at the Classifier percentage for your score.
It ends up looking that way. As an example, A-class is 75%-85% of the best scores on record, and A-class shooters make up about 15% of all classified shooters. The lower classes are represented in larger numbers and lower percentages, and the opposite is true of the higher classes, but there is no curve. The percentages required for each class has remained constant. Every shooter could be a Grand Master, if they practiced enough, had enough time and money to travel, got free ammo, someone else to take the kids to soccer tournaments, etc.