As an example, say 8 out of 10 people have 7 sets of clothes, one for each day of the week, and use the same sets for a whole year. The remaining 2 out of 10 use a new set of clothes every day, so they go through 365 sets of clothes in a year. That comes to clothes being used an average of 4.64 times:

  $ python -c 'print(
    # average used times in a year
    (
      (
        8 # people
        * 7 # sets of clothes
        * (365 / 7) # used times in a year
      ) + (
        2 # people    
        * 365 # sets of clothes
        * 1 # used times in a year
      )
    ) / (                                                        
      8 # people                                       
      * 7 # sets of clothes                           
      +                                                
      2 # people 
      * 365 # sets of clothes 
    )  
  )'                        
  4.643765903307888