It was about a thousand or less. That means on average Mary executed about 60 people per year, and Elizabeth about 20.

Mary mostly executed people for heresy, only a small minority were for treason. With Elizabeth the majority were rebels and traitors.

And then Elizabeth had the example of Bloody Mary to avoid (not least of which: to not marry is better than to marry badly). "I have no desire to make windows into men's souls" is one of the wiser things any English monarch has ever said.