private float Correlation(List<float> xList, List<float> yList)
        {
            float result = 0;

            float multiplyXYSigma = 0;
            float xSigma = 0;
            float ySigma = 0;

            float xPowSigma = 0;
            float yPowSigma = 0;
            float n = xList.Count;

            for (int i = 0; i < xList.Count; i++)
            {
                multiplyXYSigma += (xList[i] * yList[i]);
                xSigma += xList[i];
                ySigma += yList[i];

                xPowSigma += (float)Math.Pow(xList[i],2);
                yPowSigma += (float)Math.Pow(yList[i],2);
            }

            result = ((n * multiplyXYSigma) - (xSigma * ySigma)) /
                ((float)Math.Sqrt(((n * xPowSigma) - (float)Math.Pow(xSigma, 2)) * ((n * yPowSigma) - (float)Math.Pow(ySigma, 2))));

            return result;
        }