This question as written is difficult to interpret. In order to be able to provide an answer I'll make a few assumptions.

Assumption 1: you are talking about h. sapiens.

Assumption 2: by "amount" you mean the number of exons in a "gene"... (see 3)

Assumption 3: you are discussing a species that leverages alternative splicing, so when you say "gene" you mean, "across all transcript isoforms of a gene".

Assumption 4: etc .....

You can find several good answers to this question by reading past posts already asked on this forum. For example, consider: How to get number of exons for each transcript in biomart.

If after reading through this questions still remain, feel free to follow up.