Thanks for the link.
So by my calcs, it would be X2 for business class (code Z) then it is 2259 miles from KWI to COK so that would be 4518 miles RTN, multiplied by 2 to give 9036 miles.
Does that sound about right? If so, that's pretty good as both myself and my wife will be flying so it works out pretty well.
Thanks
Andrew