CGFloat period = 12; //Кол-во месяцев кредита
        CGFloat percentsValue = 15; //15%
        CGFloat percentsValuePeriod = 12; //15% годовых (12 месяцев)

        CGFloat creditSumm = 100000; //Сумма кредита

        CGFloat mainCreditPayment = creditSumm / period;

        CGFloat summToPay = creditSumm;
        NSMutableArray *payments = [NSMutableArray new];
        for (NSInteger m = 1; m <= period; m++) {
            NSMutableDictionary *dictPayment = [NSMutableDictionary new];
            dictPayment[@"main_credict_payment"] = @(mainCreditPayment);
            dictPayment[@"percents_payment"] = @(summToPay * (percentsValue/percentsValuePeriod)/100);
            dictPayment[@"month"] = @(m);

            summToPay = summToPay - mainCreditPayment;
            dictPayment[@"main_credit_summ"] = @(summToPay);
            [payments addObject:dictPayment];
        }

        NSLog(@"%@",payments);