Joshua Project organizes People Groups into Clusters: whereas there are thousands of people groups, there are only about 255 clusters. These clusters of groups are related to each other, and generally fall into one of three categories: a cluster that’s nearly all one group (e.g. Koreans), a group with a very large majority group and a few small minority groups (e.g. Turkic), and a cluster that’s made up of lots of small groups somewhat related to each other.
For each cluster, I calculated the portion of the population of that cluster’s constituent groups in each of the various UN regions. I then took the UN region’s population in 2025 and 2050, and calculated what the Cluster’s population would be if its percentage of the region remained the same (this is a big assumption, but a working start). This shows which clusters generally get bigger or remain the same or smaller, based on fluctuations in regional populations.
The result, for the least-reached clusters, is presented below. This table can show us where the remaining task could get bigger, and where it might even shrink.