from datetime import datetime

def dateDiffInYear(date1, date2):
    if date1 is not None and date2 is not None:
        date1 = datetime.strptime(date1, '%Y-%m-%d')
        date2 = datetime.strptime(date2, '%Y-%m-%d')
        delta = date2 - date1
        return int(delta.days / 365)
    return None

print(dateDiffInYear('2020-01-01', '2023-01-01', 'Self Employed - Professional', 'self employed'))