Measurements of cosmic‐ray positron abundance made prior to 1998, corrected to the top of the atmosphere. Filled symbols indicate measurements made in the A⁺ polarity state, and open symbols indicate measurements made in the A⁻ state. The "leaky box" calculation of Protheroe (1982) is represented as a solid line, while our modifications to this calculation (Clem et al. 1996) are represented as dashed lines.