There are about 4000 Er zijn zo’n 4000 tijgers over in het wild.
A number that is disputed all of the time.

Unreliable Counting
For millions of years tigers have lived on this earth, as research shows. Coming from one place (somewhere in China) they fanned out across the whole of Asia, as far as Turkey. Through evolution the tiger eventually got 9 additional subspecies, which all look alike. One is smaller than the other or more heavy and you can see differences in stripes and color. A layman can see no difference; this is reserved for scientists and experts.

One hundred years ago more than 100,000 tigers were living in Asia. Around the turn of the century there were only 6,000. In the 10 years that followed, that number was reduced with almost 50%. And in 2010 some experts said the number of tigers in the was just 2,500 although most NGOs work with the number of 3,200. And around that year tiger experts warned the tiger would go extinct in the wild  if nothing would change. Insane figures.
Figures that are very disputable because counting tigers happens to be a very unreliable process.Tigers have been counted for years and years, done in a very disputable way. Tigers were spotted, tracks were counted and more of those signals that show tigers are present in an area (like scratches on trees and excreta). Many areas where tigers live were/are totally inhospitable. And so, instead of a real count, estimated guesses were made for those areas (via extrapolation). This was and still is the basis for determining the amount of tigers that live in a particular region and/or country. 

Which makes it totally unreliable.

Nowadays it is a little better. There are other new measurement techniques (such as camera traps) and scientists are more and more able to assess parts of the inhospitable regions. But still: the count of tigers in most areas is based on odds.

The larger NGOs with scientists on their payroll claim to know how many tigers are still alive.

The truth is that nobody knows.
Why unreliable?
In 2010 the number of tigers was estimated to be around 3200 tigers, a number that is used by most NGO’s. This number was based on the before mentioned ‘calculated guessing’. Two aspects play an important role:
  1. Not all areas where tigers roam were used in counting.  In the past a scientific (in some cases not even scientific) assessment was made for a large number of areas. As more areas are now taken into account, it shows that it is precisely in these ‘new’ areas (where a low estimate was given) more tigers are being spotted than assumed before. This implies that the number of tigers has not increased but that scientists just made wrong assumptions in the past.
  2. In the last five years the instruments have improved a lot,  so the reliability of counting has risen as well. Here -too- the number of tigers has not increased (like some NGOs would like the world to believe) but it is just a result of more accurate counting.  
The official number of tigers in 2015 is 4.000. A rise of 25% in 5 years, which can be seen as good. The actual situation however shows another picture. Tigers in Vietnam, China, Lao, Malaysia, Myanmar, Indonesia and Cambodia are under enormous pressure. That is, if there are still tigers around in some countries. The populations that seem to grow are in India and Russia, however there are serious doubts about the validity of the numbers. Also because corruption is something which has to be taken into account.

The only countries where real progress seems to be made, appear to be Bhutan and Nepal.