N	Percent of non-responses	Percent of total population
Dropout	404	9.6	2.9
Dead/sick/handicapped	41	1.0	0.3
Refusal	380	9.1	2.7
Promised to answer but did not	1918	45.7	13.6
No contact	1452	34.6	10.3
Total non-responses	4195	100.0