Number of NEO – NEO pairs with D values below a limiting threshold (red line) compared to the predicted number based on random associations (blue circles with error bars) for D_sh, D′, and D_h. The blue circles represent the mean number of pairs from 500 iterations of KDE sampling using a bandwidth of 0.15, with a shaded blue region indicating a zone encompassing three standard deviations. The number of low-D value pairs corresponds very well to the predicted number based on random associations for large values; however, at very low D values, there appear to be tens of objects with statistically significant similarities. The observational biases of the dataset do not predict the elbow in the cumulative D-value plots.