Okay, in the data preparation stage, we can remove duplicates. So in Microsoft Excel, we can remove duplicates using something like this. So we this remove duplicate, so we can select a range that we create these remove duplicates here. So remove duplicates in this database, you can search on my own Google auto remove duplicates in Excel. So we remove duplicates. Then we select all and we click OK.

So we have three duplicate values, found and removed. So we have 147 unique values remain