library(openxlsx)
sample1<-read.xlsx("http://kanggc.iptime.org/book/data/sample1-n.xlsx")
#sample1_dat<- data.matrix(sample1)
#year<-sample1_dat[,1]
#gdp<-sample1_dat[,2]
#consumption<-sample1_dat[,3]

year<-sample1$year
gdp<-sample1$gdp
consumption<-sample1$consumption

data1<-sample1[1:10,]
data1

data2<-sample1[11:17,]
data2