select
avg(case when t.year = 2006 and e.name = "PRCP" and s.country_name = "United Kingdom" then o.value end)
- avg(case when t.year = 2021 and e.name = "PRCP" and s.country_name = "United Kingdom"then o.value end) as inc_PCRP,
avg(case when t.year = 2006 and e.name = "TMAX" and s.country_name = "United Kingdom" then o.value end)
- avg(case when t.year = 2021 and e.name = "TMAX" and s.country_name = "United Kingdom" then o.value end) as inc_TMAX,
avg(case when t.year = 2006 and e.name = "TMIN" and s.country_name = "United Kingdom" then o.value end)
- avg(case when t.year = 2021 and e.name = "TMIN" and s.country_name = "United Kingdom" then o.value end) as inc_TMIN
from factobservation as o
join dimelement as e on o.element_id = e.id
join dimstation as s on o.station_id = s.id
join dimtime as t on o.time_id = t.date_id;