These are the values of the 50-percentile effective diameter (δ0.5) for all networks to which the statistic applies and for which it was computed. In total, it has been computed for 1,325 networks.
The 50-percentile effective diameter (δ0.5) equals the minimal distance such that 50% of nodes pairs are at most at that distance from each other. Same-node pairs are included in the calculation, and the exact value is interpolated linearly between the two neighboring integers. Edge directions are not taken into account. In networks that are not connected, only the largest connected component is considered.
The full definition of the 50-percentile effective diameter as well as its properties and relationships to other graph statistics can be found in the KONECT handbook.