[c#] Add carriage return to a string

I propose use StringBuilder

string s1 = "'99024','99050','99070','99143','99173','99191','99201','99202','99203','99204','99211','99212','99213','99214','99215','99217','99218','99219','99221','99222','99231','99232','99238','99239','99356','99357','99371','99374','99381','99382','99383','99384','99385','99386','99391','99392'";

var stringBuilder = new StringBuilder();           

foreach (var s in s1.Split(','))
{
    stringBuilder.Append(s).Append(",").AppendLine();
}
Console.WriteLine(stringBuilder);