Here is the latest discussion on global statistics from Justin Long in his post COUNTING MISSIONARIES published on June 3, 2020:
Globally: 425,000 missionaries (Anglican, Independent, Orthodox, Protestant and Roman Catholic)
Total in World A countries: 11,940 (3%) [World A: <50% evangelized)]
Total in World B countries: 87,000 (20%) [World B: >=50% evangelized, <60% Christian]
Total in World C countries: 326,060 (77%) [World C: >=60% Christian, of any tradition]
From the summary:
2,000 years after Christ, somewhere around 3% or less of all missionary workers are deployed amongst those who have very little chance to hear (a factor in why they have little chance to hear), while three-quarters of missionaries work in places that are over-saturated Christian countries (albeit perhaps of a different tradition than the missionaries in question). While I do not doubt that places like Germany and England and France likely need evangelistic effort, this “out of balance” situation seems to me to continue to be one in need of reformation.
Read the whole thing.