I’m not sure how accurate the numbers are for actual percentage holdings, but the relative changes that have occurred over time should be fairly accurate. If you were to plot PE10 on this graph you would find a VERY high correlation. Unsurprisingly, as people become more fearful of stocks, they own less and drive the PE10 ratio lower.
Given the economic shock we are going through, fear clearly hasn’t taken hold yet. If another recession hits in the next year or two, I would expect this to get worse.