Defect depth-profiling by positron annihilation Doppler broadening was performed for single crystalline silicon wafers implanted with B(+), C(+), P(+), and As(+) having various energies. The depth profile of defects produced by ion implantation was compared with that of implanted ions using their averaged depths, R(d) and R(p). The ratio of R(d) to R(p) was found to vary systematically with dimensionless reduced energy proposed by Lindhard et al. [K. Dan. Vidensk. Selsk. Mat.-Fys. Medd. 36, 10 (1968).].