Shell scripting: case statement & numbers

Selecting a numeric range with the case statement.

case ${NUMBER} in
        [0-9]|[0-6][0-9]|7[0-5])
                                echo "${NUMBER} <= 75"
       ;;
       [7-8][0-9]|9[0-5])
                               echo "75 < ${NUMBER}<=95"
       ;;
       [9][5-9]|100)
                                echo "95< ${NUMBER} <=100"
       ;;
esac