We provided a possibility to maintain the codes manually, the necessary steps are described below.
1). Please save on your PC the attached to this email files (for Area and Region);
2). Open APM and go to Setup => Tables => Regions Editor:
3). Click on the button "Update From File":
4). Import Area Codes and then please perform the same steps for Region Codes:
After both updates are done, all previous codes will be set to the historical.
The import files are below: