
As a reward for Governance Staking, 200 million ISKs which is 20% of the total issuance (1 billion) will be distributed to Governance Stakers. White Paper

10 million ISKs will be distributed to sISK holders every year for 20 years from the time of the first reward.

Rewards are calculated by seconds in realtime. If we do the math with the total 10 million ISKs distributed per annum, 0.317 ISK is distributed per second.

The reward each individual takes every second from the entire rewards mentioned above is calculated according to the percentage of the sISK held by the individual out of the total amount of sISK circulating.
 APY is the annual rate of rewards at the time of inquiry when 1 ISK is staked according to the above formula.