select
    AGE as AGE,
    case
        when GENDER_CODE = '20' then "MALE"
        when GENDER_CODE = '30' then 'FEMALE' 
        end as GENDER,
    case
        when category_code = "10" then average_value
        when category_code = "20" then average_value
        end as H_AVG
    
from
    school_health
where
    survey_year = "2019"