If I have a list that contains 16 sublist (enclosed in 2 curly bracets),
L1 = {{{1, 1}, {1, 5}, {1, 8}}, {{2, 6}, {1, 10}, {0, 12}},
{{3, 2}, {1, 4}, {0, 15}}, {{1, 8}, {1, 14}, {2, 17}},
{{1, 2}, {2, 8}, {3, 12}}, {{2, 6}, {2, 11}, {2, 18}},
{{3, 6}, {1...