Table 6. Results of grade rating based on total scores by exterior defect investigations.
Grade
No. (Ratio)
Total score by exterior defect investigations
Grade change by correction value
Mean
S.D.
Min.
Max.
A
36 (66.6%)
15.53
9.24
0
29
B → A: 8 dams
B
9 (16.7%)
44.22
7.84
31
57
A → B: 1 dam
C
9 (16.7%)
76.56
3.02
71
83
B → C: 6 dams