In the next step, the ArcGIS 9.3 was used to prepare geographic maps of the disease incidence and frequency. 
ArcGIS 9.3
using the Raster Calculator tool. 
Raster Calculator tool
Medical journal of the Islamic Republic of Iran
Zahraei Seyed Mohsen SM ;Mohamadi Parvin P ;Moradi Ghobad G ;Shirzadi Samira S ;Azimian Fatemeh F ;Khazaei Zaher Z ;Naemi Hasan H ;Goodarzi Elham E https://orcid.org/0000-0003-2232-1860