Uh, "registered voters" represents those citizens who have established permanent residence within the city and care enough to register to vote. That's a pretty significant real-world representation of people who are allowed to vote and may actually do so.
Now, you can argue til you're blue in the face about who ought to be allowed to vote (White male landowners over the age of 21? Women? Ethic minorities? Legal immigrants? Illegal immigrants? Tourists? Felons? Domestic animals? All have been debated at one point or another).
But don't tell me that "registered voters" doesn't mean anything in the "real world."
Re: That's a pretty arbitrary number.
Now, you can argue til you're blue in the face about who ought to be allowed to vote (White male landowners over the age of 21? Women? Ethic minorities? Legal immigrants? Illegal immigrants? Tourists? Felons? Domestic animals? All have been debated at one point or another).
But don't tell me that "registered voters" doesn't mean anything in the "real world."