Withoput any familiarity with the machinations of the USA visa process (seems unbelievably complex compared to the Aussie system) I can only lok at the data in a raw statistical way.
Strikes me that you have got the classic horror story.....variable input with a fixed output.
Where the input variables are consistently positive....statistically you are on a hiding to nothing...somethings gotta give, or the lag time (process steps) will eventually catch the input curve...pain all round
If I were a Business, and assessing my performance based on these results...I would be looking for a new CEO..........!!!!