def wordcount_scoredistance(first_data, memento_data):
    """Calculates the distance between word counts given the content in
    `first_data` and `memento_data`.
    """
    score = None
    first_wordcount = len(first_data)
    memento_wordcount = len(memento_data)
    if memento_wordcount == 0:
        if first_wordcount == 0:
            score = 0
        else:
            score = memento_wordcount / first_wordcount - 1
    else:
        score = memento_wordcount / first_wordcount - 1
    return score
