How would I make the data tidy? I don't know if it is pivot_longer or pivot_wider that is appropriate here

> class (mpg2_a) [1] "list" > names ( mpg2_a) [1] "1999" "2008" >mpg2_a $ 1999 # A tibble: 31 x 4 manufacturer class cty cyl 1 audi compact 17.4 5 2 audi midsize 15 chevrolet 2 seater 15.5 8 4 chevrolet midsize 18.5 5 5 chevrolet suV 12.7 8 6 dodge minivan 16.2 5.67 7 dodge pickup 11.7 7.43 8 dodge suv 11.7 7.33 9 ford pickup 13 7.2 10 ford subcompact 16.5 7 # .. with 21 more rows $ 2008 # A tibble: 30 x 4 manufacturer class cty cyl 1 audi compact 18.6 4.86 2 audi midsize 16.5 7 3 chevrolet 2 seater 15.3 8 4 chevrolet midsize 19 5.33 5 chevrolet suv 12.7 8 6 dodge minivan 15.4 6 7 dodge pickup 12.2 7.67 8 dodge suv 12 8 9 ford pickup 13 8 10 ford subcompact 15.4 7.2 # .. with 20 more rows . Why are these data not tidy? . How can you make the data tidy? (Specific function)