More at:
http://www.avpress.com/n/02/0902_s4.hts
If I read it correctly, the June-July average is 55 passengers a day (out of 186 seats, 13 pairs of flights a week) or 15 passengers per flight (out of 50 seats).
When comparing months, keep in mind that services began June 7, so June vs July is 24 days vs 31 days. June's 1271 means 53/day, July's 1772 means 57/day, again, if I'm reading correctly.
New schedule begins Wed 9/05. There will be no evening PMD-SFO on Tue 9/04 since the plane is staying overnight to operate the inaugural 6 am departure.