I would also like to add that if you are specifically curious about consumption, in the past I could accurately calculate the monthly amount. At that time, I mixed in a 70 VG/30 PG ratio, consuming one longfill per week, meaning 480 ml per month. All this back then with an atomizer, in DL (Direct Lung), at 0.3-0.5 ohm, between 30-40 watts.
My usage method outlined above differs today, but my consumption has still remained around 500 ml per month.
I don’t know if this is a lot compared to others… perhaps a bit… or if it’s normal… but it doesn’t bother me, it is what it is. 
I assume that those who exclusively use MTL have lower consumption.