Creating a growth rate formula within a board?

does anyone know if there’s a way to create a formula that’ll automatically input growth between rows from the same reference column? specifically, I’m looking to track monthly social media followers with this set up –

one group for each social media platform. 12 rows in each group – one row for each month. first column is the number of followers on the last day of each month. next column shows the growth rate between each month.

super easy formula in excel, but can’t seem to figure out if this is possible in monday…

What’s your formula in Excel?