Not sure where are you getting 32% from. The table on p. 15 has "Systems Analysis And Programming" at 56% of all petitions. Other computer related occupations are 10.4%
"Systems Analysis And Programming" (62.2%) and "Computer Occupations, Other" (8.4%) are together 70.6% in 2017. That's the approximately the same population as "254k/365k of H1B petitions in 2017 were for computer occupations" which is about ~70%.
So 86% of of "Systems Analysis And Programming" and "Computer Occupations, Other" are "Systems Analysis And Programming".
If you want to assume "Computer Occupations, Other" are not devs, which is not a good assumption in my opinion then fine only 86% are devs.
So 86% of of "Systems Analysis And Programming" and "Computer Occupations, Other" are "Systems Analysis And Programming".
If you want to assume "Computer Occupations, Other" are not devs, which is not a good assumption in my opinion then fine only 86% are devs.