Its (according to YT comments) Mao-era accounting, in which every adult woman from 18-70 was considered a member of the Women's army. The PLA has downsized in the post-Soviet era to 2.3 million + 1.5 million reserves.
That said, the PLA still has a whole or sizable financial interest in many factorys. Many of the items you'll find at Wal-mart support this remarkable drill and ceremony.