[techsupporter]

A lot of people will point out that the difference of a relative handful of cents doesn't matter much to the individual buyer, and they're probably right. I think the change has happened largely on the supply side. Businesses didn't want to change the price of a soda and so swapped in zero-sugar versions that don't carry the tax. Anecdotally, I've noticed a distinct rise in the number of places offering several more zero-sugar options (though, for some blasted reason, it's still easier to find Coke Zero at restaurants in the suburbs than it is in the city and no, Diet Coke is not OK come on now).

(Alternatively, they did raise the price of all sodas, sugared or not, but I haven't seen much of that.)