highly significantp < 0.001
More details can be seen in Table 9 . Correlation analysis of perception among perception-related questions and other variables Kendall’s correlations were highly significant ( p < 0.001) and corelated (tau ≥ 0.4) between C1 and C2, C1 and C3, C1 and C4, C1 and C5, C2 and C3, C2 and C4, C2 and C5, C3 and C4, C3 and C5, C4 and C5.