From 1-2 glasses per day to zero for many years now.
I never was a massive fan, but I’d drink coke a couple of times a week maybe, until my early 20s. When I hit 30, I did a stint of security work, and almost all the venues I wound up working in would give us free coke or whatever other pop they had on draught from the bar, generally that being the only option (occasionally they’d offer tea and coffee, but in a busy venue they didn’t want us standing round with a hot drink). I got totally sick of it.
I very occasionally buy a bottle of pop when I’m out somewhere and forgot a water bottle, but my consumption has dropped from quite low to near 0.
I remember drinking a 2 liter bottle of Mountain Dew when I pulled all-nighters at the engineering building while in undergrad. Did this over and over.
Today I limit myself to one diet soda per day.
I am getting old. 
I grew up in the '70’s drinking Pepsi and/or Coke at every meal. Fuck that namby-pamby diet shit. I’m talking full-on extra-sugar for me, please. In my teens/twenties I found myself on steady diet of at least 2 liters of Mountain Dew a day.
The weird thing about this time in my life is that even though I’ve always been pretty active and athletic, I just couldn’t seem to lose a flabby gut. Go figure.
Anywho, one day I decided to switch to calorie-free Fresca and I dropped thirty pounds in three months without trying. Now I’m an iced-tea addict. I buy two or three 1-gallon jugs of Arizona Zero Calorie Green Tea with Ginsing a week. Beyond that, I’m a carbonated fruit-juice guy, so I do still get my share of carbonation.
I don’t generally keep soda in the house, but my wife owns a restaurant and occasionally I’ll grab one there. But in my childhood we almost always had a bottle of soda in the fridge.
I don’t generally order a beverage with meals as an adult because I’m a cheapskate and I don’t drink much while eating anyways.
EDIT: I voted “less”, but “significantly less” would probably apply as well.
I never cared much for soda. Ever. My husband drank 2 liters of Diet Coke a day and now ‘cuts’ it with polar seltzer . I like polar seltzer in any flavor (and the flavors are very faint. Peppermint tastes like a candy cane was stirred around a few times,). I like iced tea but usually drink ice water with meals.
Drank a lot of it as a teenager/young adult and never stopped. Into my 50s now and still drink about 6 Diet Cokes a day.
Significantly less, having replaced soda (pop) with beer and water. My sodastream makes water fun.
I don’t drink any soda because I’m a grown man. Soda is a child’s drink. And they shouldn’t have it either. We don’t keep any in the house and our kids only drink it at restaurants and my parents’ house.
ROFL!
You tell 'em, grown man!
LOL
Much, much more.
From occasionally a bottle here and there, to 1.5 liters a day.
Pretty much never.
If fast food places could be bothered to make decent tea, I’d never drink soda. I do fast food about once a week. So that translates to one soda a week.
I’ll go to the movies about once or twice a year where I will have a soda there as well.
Several bottles (12-16 oz) a day.
The concession to olde age is I now drink Coke Zero. I want to keep my feet into my retirement.
I drink less than I used to, which means I drink about a can or two per day down from a good 3 or 4 per day.
I’m not a coffee drinker, so soda is my go-to morning drink and my source of caffeine. I’ll always order one at a restaurant or fast food because I don’t drink beer too often (wings and pizza mostly) and I hate drinking water.
As has been stated upthread, I’ll usually buy the airplane mini-cans for my morning one at work and then I’ll have a soda at Taco Bell and refill it at least once. The reason for stopping is mostly to keep calories down.
It depends on how you define “soda.” I rarely drank it as a child (I usually drank milk), and rarely drink it now. However, my main cold beverage these days is seltzer, so if that counts, I drink far more.
Like many here, my input is pretty much zero. I will have a sprite or something maybe a couple of times a year (say on a road trip). Other than that it’s tea, water or beer. Or I’ll have a cup of coffee if I go out for breakfast.
I don’t recall how much I drank as a kid. But I don’t think very much.
I can’t remember the last time I had a soft drink, so significantly less. The closest I come to it is an occasional Limonata, but I usually can’t finish it.
Soda was for special occasions like birthday parties when i grew up.
The amount I consume is unchanged - zero. I’ve never been able to stand carbonated beverages; they give me a stomach ache.