main.cpp:

int64 GetProofOfStakeReward(int64 nCoinAge)
{
    static int64 nRewardCoinYear = CENT;  // creation amount per coin-year
    int64 nSubsidy = nCoinAge * 33 / (365 * 33 + 8) * nRewardCoinYear;
    if (fDebug && GetBoolArg("-printcreation"))
        printf("GetProofOfStakeReward(): create=%s nCoinAge=%"PRI64d"\n", FormatMoney(nSubsidy).c_str(), nCoinAge);
    return nSubsidy;
}