Look at the VASRD here (hope it works). The ratings are 10%, 20%, 40%. You can try to see where you may fit, but try to be objective. I know you want a higher rating but the jump from 20 to 40 is severe and I hope you are not that bad off.
http://www.pebforum.com/linked-veterans-affairs-schedule-rating-disabilities-vasrd/1014-vasrd-schedule-ratings-musculoskeletal-system-acute-subacute-chronic-diseases.html
http://www.pebforum.com/linked-veterans-affairs-schedule-rating-disabilities-vasrd/1014-vasrd-schedule-ratings-musculoskeletal-system-acute-subacute-chronic-diseases.html