Can someone clarify the stats a little bit? The post mentions "19 founders" and then breaks it down into 18, 15, and 4. Is the "19" an error (I notice that's 1

Can someone clarify the stats a little bit? The post mentions "19 founders" and then breaks it down into 18, 15, and 4. Is the "19" an error (I notice that's 15+4, perhaps it's missing the "18" group?), or can women be counted in multiple categories? If that's the case, it seems to me like the first category should include the second and third, so wouldn't that one be more than 19?