I need help modifying the yearly ratings given by customers. I have the data with emails and their corresponding ratings in the year. I need a scale (-1,0,1) from the change in ratings that happened for a particular email from year to year. Suppose one customer email has given a rating of 10 in 2018 and no rating in 2019 but given a rating of 8 in 2020. Then for that particular case, it should be assigned as -1 and 1 if increase in rating. If the rating is the same over the years then 0. Can someone help me with this.? Attaching the sample data for your reference. Thanks in advance.
Thanks for the solution. But in this workflow, if any customer has given a rating thrice then that case is getting ignored. Suppose any customer has given a rating of 7 in 2018 and 3 in 2020 and 5 in 2021. then for the same customer, I need -1 from 2020 and -1 from 2021.
