Table 3.

Summary statistics of stress taken in 4 measures in each analyzed cluster of oil rig workers in Poland, surveyed in 1993–2014 on oil rigs

Measure time	Stress in cluster groups (M±SD)
	1. stress resisting (N = 49)	2. stress sensitising (N = 66)	3. flexible (N = 52)
1993–1998	4.48±1.35	3.37±1.47	4.42±1.33
1999–2003	4.01±1.46	3.62±1.43	4.01±1.48
2004–2009	3.72±1.39	4.10±1.50	3.85±1.39
2010–2014	3.51±1.03	4.37±1.47	4.42±1.54