How many years would it take for the 1-24 to replace the 2-1?
return the  2-1 ;return the  1-24 replace the 2-1 ;return years of #1 ;return year of #2 ;return the  lowest of #3 ;return the  difference of #4 and  #5
['select', 'select', 'project', 'project', 'aggregate', 'arithmetic']