Distance (cm), Measured (cm),,Difference (cm)
1,3,2,1
1.5,3,2,0.5
2,3,2,0
2.5,3,2,-0.5
3,4,3,0
3.5,4,3,-0.5
4,5,4,0
4.5,5,4,-0.5
5,6,5,0
6,7,6,0
7,8,7,0
8,9,8,0
9,10,9,0
10,11,10,0
15,16,15,0
20,21,20,0
25,26,25,0
30,31,30,0
40,41,40,0
50,51,50,0
60,61,60,0
80,81,80,0
100,101,100,0
120,122,121,1
140,142,141,1
160,162,161,1
180,183,182,2
200,203,202,2