I think the Liechtenstein number could be way off as it will attract heaps of day visitors. It's so tiny its an easy say-trip, and without any customs to track comings and goings I can't see how they can measure this.
I'm just going by the source I have. I have looked at a number of different sources and Liechtenstein ranges from about 50,000 to 60,000 tourists a year so i'm confident that the source I have used is fairly accurate. I understand where you are coming from as Liechtenstein is part of the Schengen Area, however this logic should mean that we can't be sure of the tourism numbers for many European countries or even South American countries (Union of South American Nations). This would also mean we couldn't say that France has the highest number of tourists however nobody has a problem with that.I'm sure the UNWTO has considered these circumstances before publishing the data. I think this quiz topic is just one where it is difficult to find consistently accurate data.
Liechtenstein is one of only nine European countries I haven't been to. It's a bit geographically isolated and not really much reason to go out of your way to get there.
Pretty sad when your country attracts fewer tourists than Yemen or Burundi. And why is Turkmenistan so far out ahead of all it's -stan neighbors? Visa issues or something?