SWAMI Average Indicator

using System;
using cAlgo.API;
using cAlgo.API.Internals;
using cAlgo.API.Indicators;

namespace cAlgo.Indicators
{
    [Indicator(IsOverlay = false, TimeZone = TimeZones.UTC)]
    public class RelativeStrengthSWAMI : Indicator
    {
        [Parameter(DefaultValue = 14)]
        public int MaxLookback { get; set; }

        [Parameter(DefaultValue = 2)]
        public int MinLookback { get; set; }

        [Output("Main")]
        public IndicatorDataSeries Result { get; set; }

        private RelativeStrengthIndex RSIValue;

        public override void Calculate(int index)
        {
            int Period = MaxLookback - MinLookback + 1;
            double TotalSum = ReturnSum(index);

            Result[index] = TotalSum / Period;
        }

        public double ReturnSum(int argIndex)
        {
            double Sum = 0.0;
            for (int i = MinLookback; i <= MaxLookback; i++)
            {
                RSIValue = Indicators.RelativeStrengthIndex(MarketSeries.Close, i);
                Sum += RSIValue.Result[argIndex];
            }
            return Sum;
        }
    }
}

Could someone take a look at this code? It's not returning a value.

Basically I want to retrieve the relative strength values of multiple lookback periods and take the average. Right now I am not getting anything.

Any help would be great, thanks!