When does the staking reward reduce?
PoW subsidy phase: ~ 3 months, 12960 blocks x 259 NETKO = ~3,356,640 NETKO
PoS subsidy phase: ~ 8 years, 887100 blocks x 25 NETKO = ~22,177,500 NETKO
Total in this phase: 25,534,140 NETKO
After block 90000 there is a fixed PoS reward of 0.25 NETKO, adding 43800 NETKO to the supply per year