Johan,
Look in the right hand column below the stats - Download Quicktime version.

Hi Peter,
firstly it depends on how you define 'missionary'. If you would argue that every Christian is a missionary despite of their geographical location then the figure is certainly inaccurate. However, if you class a missionary as Perspectives (USCWM) "There is a tendency to define “missions” as any Christian work that takes place somewhere far away. To make things clearer
– it's sometimes better to understand a missionary to be someone working hard to reach people of a significantly different culture. By contrast, an evangelist is one who works hard to reach others of their own culture – the work of evangelism may have a lot of missionary intentions. But to best distinguish the different roles, it is best to reserve the term “missionary” for those doing, mobilizing for, or working hard in direct support of those doing cross-cultural work." then we can define the numbers better. In saying this, the figure of 100,000 is not intended to be the focus point of the video or even the initial strap line. The intended shock factor is the '3%'. Which IS accurate according to an article by Ralph Winter and Bruce Koch who estimate only 2.3% of the global missionary force of 420,000, are working to reach the unreached.
Nobody knows for sure how many missionaries there are especially as we have no way of telling how many missionaries countries like China, Laos, Burma etc are sending. The point is, the percentage working among the unreached is extremely low, moreover its tragic.