Subarachnoid Haemorrhage Incidence Pattern Analysis with Circular Statistics

Table 4

Distribution of SAH incidences in equal periods before and after each of the equinoxes.

	Freq.	Percent	Cum.
1	72	15.89	15.89
2	78	17.22	33.11
3	62	13.69	46.8
4	77	17	63.8
5	88	19.43	83.22
6	76	16.78	100
Total	453	100

The length of periods was arbitrarily selected as 1/6th of the times between the equinoxes (Pearson chi2 (5) = 4.7616, Pr = 0.446).