I know the frequencies of his "Normal Fundamental Harmonic Progressions" i.e., the progression of chord roots. I'd like to know the percentage of time that he used 1st or 2nd inversions in his chorales (where the Bass note is not the root of the chord.) Can anyone answer that?
There is a study of the subject here: https://www.gmth.de/zeitschrift/artikel/513.aspx There are also others. Some are used to build Markov chains for music simulation. Quinn's work referenced supra are a bit detailed. Just looking at major and minor triads, the split is about 63% root position and 32% first inversion and 5% second inversion.