That's natural because most of the position that is related to business, trading and such are usually held by men. Factors might be, it is natural and is already in the culture to have boys in business field making them have the highest chance of being exposed to bitcoin. But on tbe other hand, statistics doesn't guarantee the reliability of the data they got because they only had few and chosen respondents for the reference of their chart. They might have missed or maybe some have faked their genders for identity anonymity or privacy purposes. The gender doesn't count on what's important in the crypto space tho. At the end of the day it's the strategy, intelligence and practicality that counts.