Formaldehyde Vapor Concentration in Electronic Cigarettes and Health Complaints of Electronic Cigarettes Smokers in Indonesia

Table 4

Frequency of daily smoking of electronic cigarettes in personal vapor community in Surabaya city in 2016.

Frequency (time)	Percentage ()
1	8.0
2	12.0
3	12.0
4	8.0
5	4.0
6	8.0
11	4.0
12	4.0
20	4.0
Unclassified	36.0

Source: primary data.