----------------  SOLUTION  -------------------

solution cost   : 568.562
number of trips : 3

trip 1, 14 customers, sequence : 12 11 6 1 2 3 16 15 14 17 22 20 19 18 
   weight    : 3264
   volume    : 14
   trip cost : 290.109

trip 2, 2 customers, sequence : 10 13 
   weight    : 4350
   volume    : 2
   trip cost : 67.9375

trip 3, 6 customers, sequence : 7 9 8 5 4 21 
   weight    : 2575
   volume    : 6
   trip cost : 210.516