import re


def get_year(title):
    """
    Finds the last occurrence of a 4-digit number, within parentheses.
    Returns that as the suspected year of this issue's publication.
    If no match is found, return None.
    """
    match_year = re.compile(r'\((\d{4})\)')
    matches = match_year.findall(title)
    return matches[-1] if matches else None