Note:
The formulas result in a percentage of the amount of light that reaches the lens.
Think of it as: “If 100 rays of light reach a crown glass surface, 4.3 rays reflect from the front and 95.7 rays enter the lens; . . . ” etc.
Then, of the 100 rays that reached the crown glass lens, 91.8 of those rays exited the back of the lens, meaning they were transmitted through the lens.