def getRowMarker(f, year):
    """ Get the row marker for given year 
    (where the most recent update left off) and return. 
    Returns 0 if doesn't exist.  """
    dset = f['data']
    marker = 0
    if "_row_marker" in dset.attrs:
        row_marker = dset.attrs["_row_marker"]
        # returns [year, row]
        if row_marker[0] == year:
            marker = row_marker[1]
        
    return marker