-- Database schema
| incidents : case_number [ TEXT ] primary_key , date [ DATE ] , location [ TEXT ] , subject_statuses [ TEXT ] , subject_weapon [ TEXT ] , subjects [ TEXT ] , subject_count [ INTEGER ] , officers [ TEXT ] | officers : case_number [ TEXT ] officers.case_number = incidents.case_number , race [ TEXT ] , gender [ TEXT ] , last_name [ TEXT ] , first_name [ TEXT ] , full_name [ TEXT ] | subjects : case_number [ TEXT ] subjects.case_number = incidents.case_number , race [ TEXT ] , gender [ TEXT ] , last_name [ TEXT ] , first_name [ TEXT ] , full_name [ TEXT ] |
-- -- Did the number of cases with Vehicle as subject weapon increase or decrease from year 2007 to 2008. State the difference.

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