select case when y=2022 then '大四'
             when y=2023 then '大三'
             when y=2024 then '大二'
             when y=2025 then'大一'  end as grade, avg_gpa 
from(select graduate_year as y,round(avg(gpa),2) as avg_gpa
from user_profile
where graduate_year between 2022 and 2025
group by graduate_year) a
order by avg_gpa desc;