The girth of hexagon, sextet and triplet graphs

Tables of girth values of Hoare's sextet, hexagon and triplet graphs of order at most 10^9, 10^9 and 5 x 10^9 respectively, and the Python program that produced them. Two of the sextet graphs, and the bipartite double cover of one of them, have a previously unnoticed record low order (among cubic graphs) relative to the girth.