Investigate correct codes for former Netherlands Antilles

[bowsersenior]

# +599 – Former  Netherlands Antilles, now grouped as follows:
# +599 3 –  Sint Eustatius
# +599 4 –  Saba
# +599 5 – formerly Sint Maarten – Now included in NANP as code +1-721
# +599 7 –  Bonaire
# +599 9 –  Curaçao

[bowsersenior]

Apparently, the situation for the former Netherlands Antilles is now similar to that for North American and Russia/Kazakhstan. Multiple regions share the +599 code. Although this is reflected partially in the data, the data is not complete and there is no special handling for these cases to ensure proper results for the various methods.