I think they must be assuming it on the following factors.

1. No of Visitor Visa issued, 90-95% percent of the Visit visa issue are either to people who buy these visas to come and look for work, people who are visiting friends and families and people who may come to visit the sporting events. So that just leave around 5% of people who may be considered the true tourists who actually come and stay in Hotels and just you may see them wondering in Souq Waqif looking for a reasonable place to eat.

2. Also they must also include the thousands of people who are working here on Visa and just conveniently leave the country and re-enter again every two months.

3. Also they must also include people who do the similar kind of Visa runs from other GCC countries.

4. A handle full of Saudis who might come here to quence their thrist.

Now have I missed anyone?