The 1999 IAAF Grand Prix Final was the fifteenth edition of the season-ending competition for the IAAF Grand Prix track and field circuit, organised by the International Association of Athletics Federations. It was held on 11 September at the Olympic Stadium in Munich, Germany.
The IAAF Grand Prix Final is not the last event of the season
The article says it is the last event every season. i think the system is bad at sequencing