Equatorial Plasma Bubbles (EPBs) are ionospheric irregularities that occur in the post sunset, equatorial ionosphere due to the generalised Rayleigh Taylor instability. Low density plasma rises upwards and creates large field aligned regions of low density with large gradients at the boundaries. These cause amplitude and phase scintillations of L band (1-2GHz) radio signals used in satellite positioning. Therefore, as our reliance on space-based technology increases it becomes more important to understand, model, and forecast these irregularities. In order to forecast the daily variability in EPB occurrence it is important to first understand the climatology. EPBs are known to have a longitudinal and seasonal variability controlled by the angle between the magnetic field and the solar terminator. However, differences have been reported in the climatology of EPBs studied using different data sources. This work examines the caveats in the occurrence climatology of EPBs as reported from COSMIC Radio Occultation data. A new index is created to address the current limitations of the data. Using the new index the climatology matches more closely with EPB climatology reported using other data sources. The new index is recommended for future study of EPBs using COSMIC data.