It really depends on the
juice. Darker juices, thicker or very sweet juices tend to clog up cartos faster. In general I am able to run anywhere from 30 to 50 ml of
juice through a carto before the draw becomes to stiff for me. Sometimes even more. Sometimes, especially with dark/thick juices it can even happen that the carto clogs up and dies after a few tankfuls. At one point I experimented with Stevia in my juice and it killed cartos within 1-2 ml! Time is relative as it depends on how much you vape, so ml or tankfuls is a better gauge, imho.
vaping with the carto flooded also decreases its lifespan.