Bank of International Settlements has some statistics for this. The dollar is leading, but not as much as in reserves!

What: Total banknotes and coins in circulation, USD billion
When: 2017, end of year
Where: 21 major world currency
Source: BIS

P.S. The use of the donut chart requires additional justification. All the currencies together make 100%. I’m curious how much 2 biggest, 3 biggest, 4 biggest currencies make up together.