The list is about registered users. According to Wikimedia, the number of active registered Wikimedia editors for all Wikipedia projects in February 2009 was ~8

The list is about registered users. According to Wikimedia, the number of active registered Wikimedia editors for all Wikipedia projects in February 2009 was ~85,000. (https://stats.wikimedia.org/reportcard/ https://stats.wikimedia.org/reportcard/) In a more recent count (and more tightly controlled against double counts) for October 2016, that number seems to be ~65,000. (https://stats.wikimedia.org/EN/TablesWikipediaZZ.htm#activitylevels https://stats.wikimedia.org/EN/TablesWikipediaZZ.htm#activit...) Note also that activity can fluctuate based on month so that also explains the decreased number. (during the summer more students will contribute)