The Royal Netherlands Air Force purchased 213 F-16A/B aircraft the air arm was one of the four European Participating Air Forces, and one of 5 countries to build the F-16 locally. Reductions saw the fleet reduced to 68 aircraft, all of them upgraded to MLU standard. All operational F-16s operated by the Netherlands went through the Mid-Life Update (MLU) . A Multinational Operational Test and Evaluation center for the F-16A/B Mid-Life Update was set up at Leeuwarden air base in 1997. As part of on-going defence cuts, the number of F-16s to feature the upgrade was reduced from 170 to 138 in mid-1993.