Civic address problem

Program.csx

using System;
using System.Linq;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            var numbers = new[] { "1425", "33133", "3587", "2080" };

            var numberGroups = string.Join("", numbers).ToCharArray().GroupBy(key => key);

            foreach (var group in numberGroups)
            {
                Console.WriteLine($"{group.Key} Count: {group.Count()}");
            }

            Console.ReadKey();
        }
    }
}