Since the cost of maintaining a virtual currency is extremely small, there is no practical limit. Of course, some small number will dominate. For a parallel situation, look at home many Linux distros there are: http://en.wikipedia.org/wiki/Lis... That can occur because one person, with enough free time, can package there own distro. But a handful of all distros represent the majority of all Linux installations.
According to the figures in the infographic Bill Gates has given $28 Billion to various charities since 2007, which apparently accounts for almost 48% of his net-worth. One of his biggest charitable efforts has been towards the eradication of malaria and an end to polio.
With his wife Melinda, Bill Gates chairs the Bill & Melinda Gates Foundation, the world's largest private charitable foundation. The foundation works to save lives and improve global health, and is working with Rotary International to eliminate polio. Gates has topped Forbes list of the 400 richest Americans for 24 years in a row. He remains a board member of Microsoft, the software firm he founded with Paul Allen in 1975. In late 2016, Gates announced the launch of a $1 billion Breakthrough Energy investment fund with about 20 other people.