question: A list of the top 5 countries by number of invoices. List country name and number of invoices.
#1 return countries 
#2 return invoices  of   #1 
#3 return number of  #2 for each #1 
#4 return the  top 5 highest of   #3 
#5 return #1 where #3 is equal to any of   #4 
#6 return names of   #5 
#7 return #6 ,  #4