y<-c(5315,5661,5932,6312,6970,7577,8305,9559,10608,11701,13457,15687,16649,17899,19318,20114)
x1<-c(6360.5,5894.3,6610.8,7041.9,7709.9,8386,9350.1,11098.3,12633.4,13839.4,15461.2,17899.1,20307,22368,24234,26205)
x2<-c(3928.2,4293.49,4725.01,5333.09,6379.63,7385.1,9690.24,10562.39,12601.23,14151.28,17185.48,21026.68,23872.8,26392.07,28536.66,30053.1)
x3<-c(97.7,100.8,99.4,100.1,103.7,11.6,101.7,105.3,105.3,100.1,103,104.6,101.6,101.7,100.6,100.2)
x4<-c(5.1,4.37,3.89,3.12,2.78,2.9,2.86,2.92,2.39,2.72,2.31,2.98,2.97,3,3.2,3.36)