In the event of dismissal for professional incompetence, the person concerned will receive compensation equal to half the last monthly remuneration received prior to dismissal for each of the first twelve years of service, and one third of the same remuneration for each of the following years, up to a maximum of twelve times the monthly remuneration. Any period of service in excess of six months is counted as one year and any period of service of less than six months is not taken into account.