I should also add that the minimum participation requirements are calculated based on the later of your first contest or the quarter/year cutoff so as not to penalize newbs.
So, for example (and I suspect that this may be the source of your questions), the new guy, Mitt Romneys Tax Return, is eligible this week for quarterly and yearly averages because he’s participated in 100% of the contests for those periods, starting with his first. However, if he doesn’t participate next week, then his rate will drop to 50% and he’ll fall off of those reports. Also, he won’t show up on the overall lists until he racks up 50 entries.