2.6 Statistical Analysis
The Kolmogorov–Smirnov test was used to assess the normality of all variables, and the Quantile–Quantile (Q–Q) plots coupled with the skewness values, were used to evaluate the normality of the data sets (Vasu et al.,  2017). The measured EC was subjected to a descriptive analysis and minimum, maximum, mean, standard deviation, coefficient of variation, kurtosis and skewness were determined using SPSS version 23.0.