The current(mid-2019) total supply of PAL is 21 Million(with the current inflation being 10% per year).
PAL Reward Pool
PAL has "Proof-of-Brain" & "Proof of Interaction". Proof-of-Brain refers to the curating of the content on-chain(through palnet.io & on Steem blockchain). Proof-of-Interaction refers to social interaction between the community members over official discord channel of PAL and the PoI reward goes to msp-active, where the community members who partake in healthy discussions over discord channel are rewarded.
PAL has considered the practical use-case of our social interaction outside Steem blockchain. It is no wonder that majority of the Steemians interact over discord and this interaction is casual & significant, therefore encouraging this individual behaviour through a concept like Proof-of-Interaction is one of the most unique ways and PAL team should be complimented for implementing PoI concept of reward in its incentive model.