Thank you, but if I start not from 1. Here are the excel rows. The formula does not work out then:
A B C D
25.5 0.1388 25.5
25.72 0.39099 25.51
25.92 0.6259 25.52 0.01
26.13 0.85601 25.53
26.33 1.05759 25.54
26.54 1.33816 25.55
26.74 1.74156 25.56
26.95 2.12087 25.57