Well, for me it's been six months of vaping with no analogs at all.
All this time, I have found that the actual quantity I vape is going up and down. I started with 2 ml per day. Two months later, I discovered ALD 808 (ROK STAR) - which I still like very much - and hopped on to 4 ml since it was very 'tasty'. Slowly, I dropped down to 2 ml again. Nowdays I discovered cartos and I'm using them to taste lots of liquids - so the quantity has increased again.
All in all, don't worry about ml's vaped.