How many hot spots of biodiversity in the world have been identified till date by Norman Myers?

The concept of biodiversity hotspot was given by Myers who first recognized 10 hot spots that have high biodiversity. A hotspot is natural habitat that has atleast more than 0.5% of plant life as endemic species and it has lost at least 70% of its original habitat. Later on, the number of hotspots increased to 25, then 34 and currently there are 36 biodiversity hotspots in the world.