Less than 50% of tax filers in every state.
The average is about 28% of filers.
What is also needed is % of filers taking SALT deductions withing each state by income quintile (lowest 10%, next 10% ect. up to top 10%).
With the increase in the standard deduction more folks would likely have dropped SALT itemized deductions anyway, which means that alone would dropped the total number of filers to much further below 50% of all filers.
I think SALT deductions are taken by fewer filers than most people think.
I’ve seen rates in RED states that are in the 30s.