Answer:
72 million because they needed to raise cash for its development
Explanation:
It is a known fact that at lunch Ethereum had only 72 million tokens in existence back in July 2015. In other to develop the Blockchain network further, the founder, Vitalik Buterin organized a fundraising event around July and August 2014.
Fast forward to the year 2020, Ether now has a total supply of about 112 million.