Table 4 Mean, SD, skewness, and kurtosis values for each of the six quality metrics

AIG

Traditional

1^a

Mean (out of 3)

2.84

2.76

SD

0.47

0.55

Skewness

− 3.05

− 2.22

Kurtosis

8.43

3.87

2^b

Mean (out of 3)

2.89

2.78

SD

0.41

0.53

Skewness

− 3.78

− 2.42

Kurtosis

13.63

4.83

3^c

Mean (out of 3)

2.75

2.72

SD

0.61

0.65

Skewness

− 2.30

− 2.08

Kurtosis

3.69

2.66

4^d

Mean (out of 3)

2.75

2.71

SD

0.59

0.61

Skewness

− 2.23

− 1.91

Kurtosis

3.60

2.39

5^e

Mean (out of 3)

2.44

2.50

SD

0.80

0.74

Skewness

− 0.97

− 1.01

Kurtosis

− 0.75

− 0.31

6^f

Mean (out of 3)

2.15

2.08

SD

0.86

0.85

Skewness

− 0.29

0.15

Kurtosis

− 1.59

− 1.60