trying to delay a loop using yield - not working

Or I think more likely that I just don't know how to use "yield" so any help is appreciated. I couldn't find an existing answer that helped in my situation.

I'm looping through an array of objects in the scene and scoring them, but only want it to score every 3 seconds, not immediately. Here's my code:

static function StartScoring()
{
    currentGameState = GameState.Counting;

    for ( var countableObject : Rigidbody in FindObjectsOfType (Rigidbody) )
    {
        CountObject( countableObject );
        yield WaitForSeconds( 3 );
    }
}

Without the yield call, the CountObject() function appears to be called multiple times immediately as expected. With the yield call, the CountObject() function NEVER gets called at all, not even once. I don't understand why this is.

One thing I'm doing that maybe is making this interesting is I have a static GameManager object, so this function is static and Start Scoring is being called from another static function which is being called from a completely separate (non-static) game object. Is this a factor?

The only way to get a static function to work as a coroutine is to explicitly start it with StartCoroutine().