calculate sum of column SAti in LISTview in C#

Question

calculate sum of column total in LISTview in C#

 

 while (rd.Read())
 {
     usersNB.Add(new userNB
     {
         //my sql
         
         Vrijeme = rd.IsDBNull(rd.GetOrdinal("VRIJEME")) ? string.Empty : rd.GetString(rd.GetOrdinal("VRIJEME")),
         Osoba = rd.GetString("OSOBA"),
 Sati = rd.IsDBNull(rd.GetOrdinal("SATI")) ? string.Empty : rd.GetInt32(rd.GetOrdinal("SATI")).ToString()
                   


 }

Need to sum last column SATI