Considering the following dataset:
| Company name | Year | Customers |
|---|---|---|
| Company A | 2018 | 100 |
| Company B | 2018 | 120 |
| Company C | 2018 | 150 |
| Company A | 2019 | 120 |
| Company B | 2019 | 180 |
| Company C | 2019 | 80 |
| Company A | 2020 | 200 |
| Company B | 2020 | 500 |
| Company C | 2020 | 140 |
What I want to do is to measure the future return of the customers. So, I need to have the customer amount of next year in a new column. Something like this:
| Company name | Year | Customers | Customers next year |
|---|---|---|---|
| Company A | 2018 | 100 | 120 |
| Company B | 2018 | 120 | 180 |
| Company C | 2018 | 150 | 80 |
| Company A | 2019 | 120 | 200 |
| Company B | 2019 | 180 | 500 |
| Company C | 2019 | 80 | 140 |
| Company A | 2020 | 200 | NA |
| Company B | 2020 | 500 | NA |
| Company C | 2020 | 140 | NA |
Does anybody have any idea how to do this?