Before the 2008–09 season, Hoofdklasse clubs could be promoted by obtaining a professional licence. However, only a club going bankrupt or losing their license could result in clubs leaving professional football. The last clubs leaving professional football in that way were FC Wageningen and VCV Zeeland in 1992, and more recently HFC Haarlem and RBC Roosendaal, who went bankrupt in January 2010 and June 2011 respectively. The most recent additions to the league were AGOVV Apeldoorn in 2003 and FC Omniworld in 2005, expanding the league to 19 and later 20 clubs. However, for the 2010–11 season, the league returned to 18 clubs, as HFC Haarlem went bankrupt and FC Oss were relegated to the newly formed Topklasse. The 2012–13 season ended with 16 teams after AGOVV and SC Veendam went bankrupt. Four teams have been added to bring the division back up to 20 teams in 2013. Achilles '29 has been promoted from the Topklasse with the reserve teams of Ajax, FC Twente and PSV being added as well.