We have correlated the ~1 MeV proton intensity (J) measured at corotating reverse shocks detected by Ulysses in the southern hemisphere with two parameters that characterise the strength of the shock. Between 6¿--29¿S J is essentially independent of the shock strength, whereas between 29¿--41¿S J is well correlated with the same. The poor correlation from 6¿S to 29¿S is attributed to variations in the background intensity caused by changes in solar activity. Our results also show that J is independent of the shock normal angle at all latitudes. We compensate for the effects of a fluctuating background by assuming that reverse shocks associated with two adjacent compression regions observed during a ~26 day period accelerate particles out of the same seed population. The relation between the ratio of the proton intensities and the ratios of the shock parameters for such reverse shock-pairs indicates that the shock acceleration efficiency increases with the shock strength but is independent of the normal angle.¿ 1997 American Geophysical Union