It’s less that 90% drop out before level 10, and more than once past level 3, 5% of users drop out every level, and that starts to add up. The graphs don’t distinguish between the types of non-lifetime subscriptions, mind - I don’t think that information is available unless you’re in the backend - and be aware that “free”, when they’re above level 3, means they had a non-lifetime subscription which has lapsed.