This is an interesting question, to which I do not have “very good” answers. I’m posting this on the off chance that someone from that region can help us further.

The last really good globally comprehensive survey of missionaries sent was done for the 2001 edition of Operation World.

That work said 10,192 missionaries (Protestants, Independent, Anglicans only) from 346 agencies, of which 3,827 served in other countries.

(The balance, 6,365, worked in Latin America itself.) There was no indicator of how many were sent from Latin America to specific areas.

Of course, 2001 saw the 9/11 event and the massive security clampdown afterwards.

The 2010 edition of Operation World was not able to do a globally comprehensive survey of missionaries sent.

But, considering the enormous mission emphasis in Latin America’s Protestant community (of which COMIBAM is the most visible example), it is doubtful that the numbers have slackened off.

I asked DM, who knows the region very well, and his opinion was that somewhere between 6,000 and 8,000 were sent out, about half to unreached groups (defined as below 2% evangelical).

While he wasn’t offering a precise number, it was informed by his long-term experience in the region, and it jives quite well with the Operation World estimate.

Some other data points:

• 2007: “Out of 9,000, only 2,000 are serving outside Latin America” (partially because many must serve cross-culturally in Latin America before they are considered for Asia or Africa)
• 2012: “Over the years, COMIBAM has sent over 15,000”
• COMIBAM video: 25 years after Sao Paulo 87 Comibam congress, 15,000 work in Latin America and abroad. (Jives with the OW number of 10,192 total.)
• COMIBAM 1984-2000: Historical analysis of a Majority World missionary network, Guarneri, Julo S., Dallas Baptist University, 2013, 325 pages. Downloadable PDF.

(By comparison, in 2001 the USA sent about 60,000 long-term workers to 220 countries.)