It is because the system did not aggregate two different quantity units. If you only need the values, use the option ''Ignore quantity units differences''  There are the list of standard country groups: America LAIA 32 +68 +76 +152 +170 +192 +218 +473 +484 +600 +604 +858 +862APEC 490 +36 +96 +124 +152 +156 +344 +360 +392 +410 +458 ...