In 2001, Barrett and his colleague Todd M. Johnson started collecting statistics on martyrs. In their seminal work World Christian Trends AD 30 AD 2200 (Pasadena: William Carey Library, 2001), they assessed that up to the year 2000 there had been some 70 million Christian martyrs, of which 45 million were concentrated in the 20th century. The book explained the methodology used, and defined Christian martyrs as «believers in Christ who have lost their lives prematurely, in situation of witnesses, as a result of human hostility». Being «in situation of witnesses», the authors explained, means that one can become a martyr «consciously or unconsciously». They counted as Christian martyrs those killed because of their status of «Christian believers» ascribed to them by those who killed them, irrespective of whether they were at the time of their killing «actively proclaiming» the faith. But the count did exclude those killed for national, ethnic or political reasons who just happened to be Christian but were not killed because of their being Christian.
Again, statistics is a very contentious field but the book, although not without critics, is still widely respected and quoted in the academia. After their book, Barrett and Johnson have constantly updated their statistics about martyrs. In their last update, Christianity 2011: Martyrs and the Resurgence of Religion, published in the issue for January 2011 (vol. 35, n. 1) of their International Bulletin of Missionary Research, they noted that the number of Christian martyrs per year peaked at around 160,000 in the year 2000 because of local situations, including in Sudan. Since conditions in Sudan and elsewhere became subsequently less dramatic, their «confident» estimate for the year 2010 is of 100,000 Christian martyrs. They also expect the figure of 100,000 to be substantially replicated in 2011.
New martyrdom situations, however, have arisen. The largest currently is in the Democratic Republic of Congo (DRC), where atrocious acts of violence began in the late 1990s and continue to the present. According to the International Rescue Committee, from 1998 to 2007 there were approximately 5.4 million excess deaths in the DRC. While some deaths are directly related to violence, most victims died from indirect causes, such as disease or starvation. These deaths occurred mainly in five insecure eastern provinces, and the vast majority of those killed in the DRC were Christians. Although not all their circumstances would be considered situations of witness, we estimate that a substantial
proportion of those who died meet our definition of martyr