Please see FAQ: What's a reproducible example (`reprex`) and how do I do one?. Screenshots are generally unhelpful.
See if you can apply this approach
suppressPackageStartupMessages(library(dplyr))
mtcars %>% group_by(gear) %>% count() %>% mutate(pct_tot = n/nrow(mtcars)*100)
#> # A tibble: 3 x 3
#> # Groups: gear [3]
#> gear n pct_tot
#> <dbl> <int> <dbl>
#> 1 3 15 46.9
#> 2 4 12 37.5
#> 3 5 5 15.6
Created on 2020-02-17 by the reprex package (v0.3.0)