Table 1

Description of the sample

	Sample per survey			Sample in total
	2009	2013	2016	Observations	Individuals
Gross sample*	20 136	20 492	20 272	60 900*
Net sample†	12 255	10 875	10 665	33 795	20 341
Response percentage	60.9	53.1	52.6	55.5
Working population‡	9279	8375	8329	25 983	15 866§
Active employee relationship of at least 50 days¶	7709	7077	7302	22 088	13 731
Eligible sample**				21 671	13 473

*Randomly drawn population sample (*maximum number of possible observations).
†Total number of respondent including employed and non-employed individuals.
‡Respondents who were in paid work for at least 1 hour during the interview week, or were temporarily absent from such work were interviewed about working conditions.
§Sum of individuals that were interviewed about working conditions in one survey (n=8504), two surveys (n=4607) and three surveys (n=2755).
¶Registered with an active employee relationship of at least 50 actual working days in the survey year and the following year in the sickness absence register.
**Eligible sample after deletion of respondents with missing values (n=258 (1.9%) individuals).