Sparsity of Hamiltonian and overlap matrices

We are currently running tests to implement Scalapack, and are jotting down the percentage of zeros in the test system (a zero is considered when its < 1e-8), the test system is Sc3N@C80-Phtalocyanine.
For the Hamiltonian matrix: out of 11,117,970 upper triangular elements, 5,009,259 correspond to zeros (45%)
For the overlap matrix 5,384,683 are zeros (48%)