Table 4. Port intra-dependency ratio overview

Port intra-dependency ratio	Busan (%)	Singapore (%)	Shanghai (%)
Busan	11.34	-	-
Singapore	-	39.62	-
Shanghai	-	-	26.37
Busan - Singapore	2.65	1.83	-
Busan - Shanghai	36.53	-	22.16
Singapore - Shanghai	-	24.41	21.45
Busan - Singapore - Shanghai	49.48	34.15	30.01
Total	100.00	100.00	100.00
Variance of the dependency ratio	4.73	2.78	0.16