“From the very first, the Moravians recognized that the evangelization of the world was the most pressing of all the obligations that rested upon the Christian Church, and that the carrying out of this obligation was the “common affair” of the community. From 1732 to 1930, they sent out nearly 3,000 missionaries, the proportion of missionaries to their communicant membership being one in twelve.”
Concise History of the Christian World Mission by Herbert Kane
It’s about 1 in 3,200 in Southern Baptist Convention, and about 1 in 5,000 for the other Protestant denominations.