Y X1 X2 3.9 1.5 2.2 7.5 2.7 4.5 4.4 1.8 2.8 8.7 3.9 4.4 9.6 5.5 4.3 19.5 10.7 8.4 29.3 14.6 14.6 12.2 4.9 8.5