| Mean | Standard deviation | Skewness | Kurtosis |
I1 | 2.70 | 1.26 | 0.31 | −0.82 |
I2 | 2.48 | 1.19 | 0.59 | −0.55 |
I3 | 2.66 | 1.24 | 0.33 | −0.79 |
I4 | 2.68 | 1.20 | 0.41 | −0.62 |
I5 | 2.65 | 1.28 | 0.36 | −1.00 |
I6 | 2.68 | 1.22 | 0.40 | −0.74 |
I7 | 2.65 | 1.18 | 0.31 | −0.77 |
I8 | 2.24 | 0.98 | 0.54 | −0.17 |
I9 | 2.27 | 1.04 | 0.62 | −0.12 |
I10 | 2.28 | 1.05 | 0.40 | −0.76 |
I11 | 2.23 | 0.96 | 0.71 | 0.32 |
I12 | 2.29 | 1.01 | 0.53 | −0.19 |
I13 | 2.21 | 0.94 | 0.47 | −0.43 |
I14 | 2.80 | 1.20 | 0.15 | −0.79 |
I15 | 2.68 | 1.24 | 0.41 | −0.79 |
I16 | 2.74 | 1.23 | 0.18 | −0.81 |
I17 | 2.81 | 1.24 | 0.27 | −0.85 |
I18 | 2.73 | 1.25 | 0.20 | −0.94 |