Guys, let's not rush to assume on the basis of the last 2 draws that 3000 ITAs per draw will be the norm now. We are nearing the end of the summer season in North America. People are taking their last vacations now. Monday September 4 will be Labour Day in Canada, which marks the end of the summer vacation season in Canada (as well as the US). After that, people go back to work and school and things pick up. I think it's entirely reasonable to expect more ITAs per draw (and declining scores) in September and beyond.
Also note from last year's history that in the summer months June through August, the average number of ITAs per draw was around 750. Then the first draw of September had 1000 ITAs and kept increasing with semi monthly draws until the final draw of the year had 2,878 ITAs.
http://www.canadavisa.com/express-entry-invitations-to-apply-issued.html
As others have mentioned in the previous ROH thread, CIC issues ITAs based on their projected capacity to process them in their targeted timeframes (i.e., 6 months from receipt of application). They have less capacity in the summer months because North Americans, especially government workers, like to take vacations in the summer.
Full list of 2017 holidays in Canada:
https://www.timeanddate.com/holidays/canada/