Estimated and imputed year-to-year retention rates (Y2YRR) and cumulative UCP rates for authors based on ending year and number of continuous publishing years previous to ending^*.

*UCP rates for earlier years that have been estimated by extrapolation using year-to-year retention rates (Y2YRR) from the more recent data are shown in bold type. Estimated (by extrapolation) numbers of authors who ceased publishing in the ending year after having published continuously for 16 years are listed at the bottom of the table.