Table 4. The statistically significant differences between the different age groups (P value).

	≦25	26–30	31–35	36–40	41–45	46–50	51–55	≧56
≦25		<0.001	<0.001	<0.001	<0.001	<0.001	<0.001	0.160
26–30			0.287	0.002	0.051	0.242	0.089	0.235
31–35				0.041	0.344	0.815	0.270	0.076
36–40					0.318	0.120	0.981	0.004
41–45						0.54	0.588	0.023
46–50							0.362	0.066
51–55								0.020
≧56