I have achieved your objective by constructing the sql query in following way:
SELECT min(Day) time , SUM(CY-3) ‘2019’, SUM(CY-2) ‘2020’, SUM(CY-1) ‘2021’, SUM(CY) ‘2022’ FROM (
SELECT
Day, month(Day) ‘Maand’,
max(case WHEN year(Day)=year(CURRENT_DATE) then graad_dag else 0 END) ‘CY’,
max(case WHEN year(Day)=year(CURRENT_DATE)-1 then graad_dag else 0 END) ‘CY-1’,
max(case WHEN year(Day)=year(CURRENT_DATE)-2 then graad_dag else 0 END) ‘CY-2’,
max(case WHEN year(Day)=year(CURRENT_DATE)-3 then graad_dag else 0 END) ‘CY-3’
FROM hist_utils
WHERE year(Day)>year(CURRENT_DATE)-4
GROUP BY Day) as a
WHERE 1
GROUP BY Maand
ORDER BY Maand;
And the graph looks like this:
