Patent Milestone in August?

The USPTO is on track to issue patent no. 8,500,000 later this summer. At the current rate of about five thousand new patents each week, no. 8,500,000 should appear sometime in August. Patent no. 8,000,000 was issued on August 16, 2011, just two years ago. It took over 100 years, from 1790 to 1911, for the U.S. to issue its millionth patent. Since that time, the interval has been steadily decreasing. At the current rate patent no. 9,000,000 will issue in 2015.

U.S. Patent Milestones

Year No. Interval
2011 8,000,000 5 years
2006   7,000,000 7
1999 6,000,000 8
1991 5,000,000 15
1976 4,000,000 15
1961 3,000,000 26
1935 2,000,000 24
1911 1,000,000 121