Early X-ray workers: an effort to assess their numbers, risk, and most common (skin) affliction

Insights into Imaging

Table 5 Estimated number of German X-ray users (with standard deviation)

	1905	1906	1907	1908
From DRG-members (sd)^a	810 (256)	769 (187)	990 (231)	1170 (275)
From DRG-congress visitors (sd)^a	1022 (194)	627 (144)	838 (218)	1011 (261)

^a standard deviation reflects Chapman’s uncertainty only, total uncertainty larger (Appendix 2)