Among the episodes that were aired in 1998, how many won an International Monitor Awards?
aired in 1998 refers to air_date like '1998%'; won refers to result = 'Winner'; International Monitor Awards refers to organization = 'International Monitor Awards'
SELECT COUNT(T1.episode_id) FROM Episode AS T1 INNER JOIN Award AS T2 ON T1.episode_id = T2.episode_id WHERE strftime('%Y', T1.air_date) = '1998' AND T2.organization = 'International Monitor Awards' AND T2.result = 'Winner'