def create_average_data(json_data):
    """

    Args:
        json_data -- School data in tree structure.
    Returns:
        dict -- Average of financial data across schools that provided data.
    """
    avg = {}
    counts = {}

    for school in json_data:

        for year in json_data[school]:
            if year < 2005:
                continue
            if year not in avg:
                avg[year] = json_data[school][year]
                counts[year] = {}
                for elem in json_data[school][year]:
                    counts[year][elem] = 1
            else:
                for elem in json_data[school][year]:
                    if elem not in avg[year]:
                        avg[year][elem] = json_data[school][year][elem]
                        counts[year][elem] = 1
                    else:
                        avg[year][elem] += json_data[school][year][elem]
                        counts[year][elem] += 1

    for year in avg:
        for elem in avg[year]:
            avg[year][elem] = avg[year][elem] / counts[year][elem]

    return avg