Q. Of that number, are you aware of approx. how many of those fossils have been proven to be transitional forms ” showing an evolutionary state between one clear species and another?
This question is very flawed. Today there are separate species (populations which do not share a gene pool) which we can NOT tell apart by looking at them with all their organs and fleshy parts there. It has taken either detailed field studies or genetics to determine that they are separate species.
There is very, very little chance of species that have just undergone speciation to be recognizable from fossils alone.
A "transitional" between
species is something that one could argue can't really be defined. Since lions and tigers can still (after a small number of millions of years of separation) interbreed (and apparently produce fertile offspring sometimes) are they "transitionals" between something and something else?
Speciation is going on now and has been observed. But it is indeed fairly subtle and is very, very unlikely to show a record in fossils.
Historically the argument over transitionals has been well above the species level. So your question is rather odd.
Even YEC creationists agree that speciation happens and many think it happens at an extraordinarily fast rate. The transitionals aregued about are between things like land animals and whales, fish and amphibians, reptiles and mammals, other primates and humans etc. None of these transitions are anywhere near the species level.