Sad, but not enexpected to see the rewardpool going down.
I understand why people self-vote, but I think the network as a whole should disincentivize such behaviour. Voting for your own post I think is OKAY, seeing as you want some exposure and you're already heavily invested in the network.
In the end the network just has to find a structure optimizes the balance between incentivization to create content (comments/posts) and incentives for curating content (upvoting others, not yourself).
Cool that people provide these stats, keep it up :)
We will see how it goes with the next Hard Fork....