While I was drafting another comment and doing some brief preliminary research for it, I came up with this question. I already know how to find the answer, but just for fun, I'll now present it as a betting game for you guys before I analyze and reveal it.
Out of all Key Bus Routes (edit: except 71 and 73) (1, 15, 22, 23, 28, 32, 39, 57, 66, 71, 73, 77, 111, 116/117), and a few other routes with route-specific data available (SL4, SL5, 9, 16, 21, 34/34E, 47, 61/70, 86, 104), in 2022 (largely post-Covid), which bus routes have the lowest and highest proportion of riders taking it for home-based work, respectively? (In other words, which routes are the most and least commute-centric?)
