How do I make a class iterable?

This is my class

public class csWordSimilarity
{
    public int irColumn1 = 0;
    public int irColumn2 = 0;
    public int irColumn3 = 0;
    public int irColumn4 = 0;
    public int irColumn5 = 0;
}

I want to make that class iterable to be used like the way below

foreach (int irVal in myVarWordSimilarity)
{

} 

myVarWordSimilarity is csWordSimilarity type. So I want to iterate all public int variables. How do I need to modify csWordSimilarity class for making it iterable like the way above.