IF, THEN Statement for completing Final Rating

I have two columns "Initial Rating" & "Final Rating". The "Initial Rating" column has four levels of severity (Pass, Minor, Moderate, Severe) at least one of these severity levels is reflected on each row. The "Final Rating" column also uses these same four levels of severity, but not all rows have a level of severity reflected on each row. What I'm trying to accomplish is to write an IF statement that reads the "Final Severity" column, and if a level is shown in that row, to skip to the next row down. If that row does not have anything shown, then I'd like the IF statement to read the "Initial Rating" column and populate the Initial Rating, into the Final Rating. I've attached an image of what my report looks like.