R-D personnel by sector of employment and field of science presents research and development (R&D) personnel statistics for total R&D personnel by sector of employment and field of science, in full-time equivalent on R&D; Researchers by sex, sector of employment and field of science, in full-time equivalent on R&D; Researchers by sex, sector of employment and field of science, in headcounts. Sectors of employment include business enterprise, government, higher education, private non-profit and total. Breakdown by field of science includes natural sciences, engineering, medical sciences, agricultural sciences, social sciences, and humanities. Data are presented from 1981 onwards and are expressed in terms of units for personnel with full-time equivalent on R&D activities as well as headcounts.