a for loop problem

im supposed to get 100500 but with this code im getting 1000

 

using System;


namespace HelloWorld
{
class Program
{


static void Main(string[] args)
{
int lowerBounds = 1;
int upperBounds = 1000;
int sum = 0;

for (int i = lowerBounds; i <= upperBounds; i++)
{
if (i % 5 == 0)
sum += 5;
}
Console.WriteLine(sum);
Console.ReadLine();
}

}
}