task is to develop a regression model that Efes can use to predict beer sales in Turkey.

Should I convert the years in column one to categorical variable (factor) or should I use them as numerical variable and assign numbers starting from 0 to each year such as

assigning value 0 to 1987

1 to 1988

2 to 1989

3 to 1990 etc

here is the link to the excel sheet

https://drive.google.com/file/d/1TgvD7fHpv8h03IDM0HPpTNfTKcFWOLqt/view?usp=share_link