CREATE TABLE bridge (architect_id NUMBER, id NUMBER, name CLOB, location CLOB, length_meters FLOAT, length_feet FLOAT)
CREATE TABLE architect (id CLOB, name CLOB, nationality CLOB, gender CLOB)
CREATE TABLE mill (architect_id NUMBER, id NUMBER, location CLOB, name CLOB, type CLOB, built_year NUMBER, notes CLOB)

How many mills of 'Grondzeiler' type are built in each year? Give me the trend.
SELECT built_year, COUNT(built_year) FROM mill WHERE type = 'Grondzeiler'
SELECT "built_year", COUNT("built_year") FROM "mill" WHERE "type" = 'Grondzeiler'