what was the last time of patient 70709 catheter tip-iv microbiology test since 142 months ago?
select microbiologyevents.charttime from microbiologyevents where microbiologyevents.hadm_id in ( select admissions.hadm_id from admissions where admissions.subject_id = 70709 ) and microbiologyevents.spec_type_desc = 'catheter tip-iv' and datetime(microbiologyevents.charttime) >= datetime(current_time,'-142 month') order by microbiologyevents.charttime desc limit 1