/*distribution of capital gain groups per marital status*/
SELECT maritalstatus, 					
       SUM(CASE WHEN capitalgain >= 75000 THEN 1 ELSE 0 END) as num_75000,	
       SUM(CASE WHEN capitalgain >= 50000 AND capitalgain < 75000 THEN 1 ELSE 0 END) as num_50000,
       SUM(CASE WHEN capitalgain >= 25000 AND capitalgain < 50000 THEN 1 ELSE 0 END) as num_25000,
       SUM(CASE WHEN capitalgain < 25000 THEN 1 ELSE 0 END) as num_1
FROM person					
GROUP BY maritalstatus
ORDER BY 2 DESC;