Decade is a different concept from Century. Century is related to History. you are likely to find Horse in/at/on History. Horse is related to Relative. 
Cab is a type of Car. Car is related to Wheel. Wheel is related to Brake. 
Decade <--DistinctFrom--> Century <--RelatedTo--> History <--AtLocation-- Horse <--RelatedTo--> Relative 
Cab --IsA--> Car <--RelatedTo--> Wheel <--RelatedTo--> Brake 