Variable Frequency Percentage (%)
Age-distribution    
30 – 40 304 60.8
41 – 50 138 27.6
51 – 60 58 11.6
Total 500 100.0
Sex of the subjects    
Male 300 60.0
Female 200 40.0
Total 500 100.0
Educational status    
No education 2 1.6
Primary education 61 12.2
Secondary education 164 32.8
Post secondary 267 53.4
Total 500 100.0
Occupation    
Trading 191 38.2
Civil servant 245 49.0
Artisan 64 12.8
Total 500 100.0
Subject’s monthly income (N)     
< 100,000 330 66.0
100,000 – 199,000 98 19.6
200,000 – 299,000 43 8.6
300,000 – 399,000 12 2.4
400,000 above 17 3.4
Total 500 100.0
Table 1: Socio-demographic characteristics of the healthy subjects.