Database schema:

CREATE TABLE incidents (
	case_number TEXT NOT NULL, 
	date DATE NOT NULL, 
	location TEXT NOT NULL, 
	subject_statuses TEXT NOT NULL, 
	subject_weapon TEXT NOT NULL, 
	subjects TEXT NOT NULL, 
	subject_count INTEGER NOT NULL, 
	officers TEXT NOT NULL, 
	PRIMARY KEY (case_number)
)


CREATE TABLE officers (
	case_number TEXT NOT NULL -- example: ['121982X', '44523A'],
	race TEXT -- example: ['L', 'W'],
	gender TEXT NOT NULL -- example: ['M', 'F'],
	last_name TEXT NOT NULL -- example: ['Fillingim', 'Patino'],
	first_name TEXT -- example: ['Brian', 'Michael'],
	full_name TEXT NOT NULL -- example: ['Fillingim, Brian', 'Patino, Michael'],
	CONSTRAINT fk_officers_incidents FOREIGN KEY(case_number) REFERENCES incidents (case_number)
)


CREATE TABLE subjects (
	case_number TEXT NOT NULL -- example: ['121982X', '44523A'],
	race TEXT NOT NULL -- example: ['L', 'B'],
	gender TEXT NOT NULL -- example: ['M', 'F'],
	last_name TEXT NOT NULL -- example: ['Curry', 'Chavez'],
	first_name TEXT -- example: ['Gabriel', 'James'],
	full_name TEXT NOT NULL -- example: ['Curry, James', 'Chavez, Gabriel'],
	CONSTRAINT fk_subjects_incidents FOREIGN KEY(case_number) REFERENCES incidents (case_number)
)

Question: Did the number of cases with Vehicle as subject weapon increase or decrease from year 2007 to 2008. State the difference.
Evidence: number of cases refers to count(case_number); with Vehicle as subject weapon refers to subject_weapon = 'Vehicle'; year 2007 refers to date between '2007-01-01' and '2007-12-31'; year 2008 refers to date between '2008-01-01' and '2008-12-31'

SQL:
SELECT SUM(IIF(STRFTIME('%Y', date) = '2007', 1, 0)) - SUM(IIF(STRFTIME('%Y', date) = '2008', 1, 0)) FROM incidents WHERE subject_weapon = 'Vehicle'