Table 2.

Helmet use per 100 person-minutes of observation

	Ridersa	Pillion ridersa	Totalb
Helmet use	77.8	36.3	57.1
Standard helmet use	50.7	21.8	36.3
Full-face helmet use	43.9	16.8	30.3
Proper helmet use	34.9	14.0	24.5
Effective helmet use	29.2	9.8	19.5

Use per 100 person-minutes of observation = (Number of users × 100)/D

D (Denominator) = Number of data collectors × number of days × (number of minutes/day)

^aFor Riders/Pillion riders = ( 1 × 28 × 90) = 2520 person-minutes of observation

^bFor total motorcyclists (riders + pillion) = (2 × 28 × 90) = 5040 person-minutes of observation

Example for helmet use (riders) = 1961 × 100 /2520=77.8 helmet users per 100 person-minutes of observation