from typing import List


def castorize_year_column(data: List):
    """Castorizes a year column and replaces errors with 'Error'."""
    new_list = []
    for datapoint in data:
        if datapoint is None:
            new_list.append(None)
        else:
            try:
                # Test if the data point is year-like. Sorry people from before 1900 and after 2100
                if 1900 < int(datapoint) < 2100:
                    new_list.append(datapoint)
                else:
                    new_list.append("Error")
            except ValueError:
                new_list.append("Error")
    return new_list