Assign ordinal label to numbers, based on this post https://stackoverflow.com/questions/40039903/r-add-th-rd-and-nd-to-dates

ord_nums.R

ord_nums <- function(n){
  
  ord <- ifelse(n %in% c(11,12,13),  "th",
                ifelse(
                  n %% 10 == 1, 'st',
                  ifelse(
                    n %% 10 == 2, 'nd',
                    ifelse(
                      n %% 10 == 3 , 'rd',  "th"
                    )
                  )
                )
          )
  
  return(paste0(n, ord))
}