fn (1) 1=0.3 16=5.3 . 2=0.7 17=5.7 . 3=1.0 18=6.0 . 4=1.3 19=6.3 . 5=1.7 20=6.7 . 6=2.0 21=7.0 . 7=2.3 22=7.3 . 8=2.7 23=7.7.