What are the frequency of HFT

Some data collected for High Frequency Trading:

penny made each, 40 Million per day=> 1.5 Trades per ms =>42M per 7 hour period(9:30-4:30)
HFT account for 70% trades in the market, use to be only 30%.
At open Citadel executed 20M shares in 3 minutes --- HFT and Market Maker, 14% of Market trades