Table 1.

 Number of observations per year

Year	No of observations
	Mental fatigue	Physical fatigue	Depressive symptoms	Chronic conditions*
−7	10 339	10 390	1 008	10 471
–6	11 067	11 053	1 227	11 884
–5	11 455	11 455	1 492	12 655
–4	11 354	11 357	2 226	12 878
–3	11 825	11 832	2 463	13 577
–2	11 958	11 967	2 729	13 894
–1	12 050	12 059	2 903	14 104
0	12 076	12 091	3 137	14 104
1	12 524	12 537	3 527	14 104
2	12 315	12 328	3 186	13 597
3	12 067	12 091	3 205	13 183
4	11 748	11 768	3 678	12 622
5	10 706	10 718	2 547	11 512
6	9 426	9 448	2 156	10 098
7	7 967	7 972	2 386	8 477

*Number of person years with any of respiratory disease, diabetes, or coronary heart disease/stroke (assessments carried forward between first and last measurement if missing in particular year).