I have a series of times in column 1. The times are 1.1, 1.1, 1.1, 1.2, 1.2, 1.2, 2.1, 2.1, 2.1 etc. I want to assign a unique number to each of these times. In order words, each time series should have its own number. Eg, all 1.1 should be assign the number 0, all 1.2 to the number 1 etc. A unique number to each series or repeating time. Any thoughts?