Table 2.

Incidence of appearance in different age groups.

Age group	aMFL	pMFL	aMFL + pMFL	Absent
20–30 y	17	132	24	1
31–40 y	13	57	29	2
41–50 y	16	77	16	2
51–60 y	8	33	8	10
>60 y	5	23	4	23