List all airlines. For every airline, compute the number of regional airports (full name of airport contains the string 'Regional') from which that airline does NOT fly, considering source airport only. Sort by airport count in descending order.

Tables:

airlines.csv Id : unique identifier of the airline Name : full name of the airline Abbr : abbreviated name of the airline Country : country of the airline

airports.csv City : location of the airport Code : unique three-letter airport code Name : name of the airport Country : country of the airport CAbbr : abbreviation of the country

flights.csv Airline : airline that manages the flight FlightNo : flight number (unique for each airline, may repeat for different airlines) Source : Code for the airport from which the flight originates Destination : Code for the airport at which the flight terminates

Wanted Output:

Northwest Airlines	2
Southwest Airlines	2
United Airlines	2
AirTran Airways	1
Allegiant Air	1
American Airlines	1
Delta Airlines	1
Frontier Airlines	1
JetBlue Airways	1
Virgin America	1
Continental Airlines	0
US Airways	0

PLEASE EXPLAIN