So by 50 posts you mean 50 comments as there is just a single Blog post in your account, so the rest is only comments I guess?
There are multiple factors at play on how much you manage to earn, what you post about, how you are writing, are you good at attracting and keeping readers, and even if you are lucky enough to get noticed by a whale.
But I guess you need to write posts and not rely only on comments if you want to earn more. Even if you are good in every aspect you may still remain unnoticed and end up with not much earnings, so here the rewards should not be your goal. If you manage to get some it will be fine, but you should not be focusing on that and with some luck you may actually get a trending post :)