question: How many people, in terms of percentage, were either of German, Irish, or American ancestry?
#1 return people 
#2 return ancestry of #1 
#3 return #2 that is German 
#4 return #2 that is Irish 
#5 return #2 that is American 
#6 return percentage of #3 
#7 return percentage of #4 
#8 return percentage of #5 
#9 return sum of #6 and  #7 
#10 return sum of #8 and  #9