There are 31 days in May. If someone rode 30+ miles every day then they'd get 124 mileage points. If they got all the medals that would be another 102 points. And the daily trip points would be either 93, 62, or 31 depending on if they were a novice, veteran, etc.
So the max points a person can have at the end of the month is as follows:
319: novice, big wheel
288: veteran, weekend warrior
This means a team could finish with as many as 1595 points if all members were novices
Also it looks like one person is "ahead of the curve" with 180 points. This is 56.4% of the theoretical maximum of 319 and right now we're only 54.8% of the way through the month. But they've already claimed most of the medal points so those percentages will flip the other way around eventually.