During unstable stock market times, what percentage of trading is 'computer generated'?

Factual Questions
1

For days like yesterday or as today is becoming, can we estimate the dollar value percentage of Wall Street (and other markets’) transactions that are being directly made by humans as opposed to being computer/program generated?

As I understand it (which I freely admit is not much), automatic buys/sells kick in whenever pre-established thresholds have been reached. I assume many of those thresholds have been met multiple times this week.

How much autopilot is the market on?

2

A quick Googling gives some older estimates of 80-90% of trades are computerized, with more on volatile days. I don’t believe that is remotely close now. It’s got to be well over 99.9% given that a phenomenal amount of trades are rapid fire, fully automated ones.

Another quick check: The volume on the 19th of the DJIA was 240,640,000, yesterday it was 664,980,000. The cpus were busy that day, my friend.