when did it first happen on 03/01/2103 that the respiratory rate of patient 31300 was less than 19.0?
select chartevents.charttime from chartevents where chartevents.icustay_id in ( select icustays.icustay_id from icustays where icustays.hadm_id in ( select admissions.hadm_id from admissions where admissions.subject_id = 31300 ) ) and chartevents.itemid in ( select d_items.itemid from d_items where d_items.label = 'respiratory rate' and d_items.linksto = 'chartevents' ) and chartevents.valuenum < 19.0 and strftime('%y-%m-%d',chartevents.charttime) = '2103-03-01' order by chartevents.charttime asc limit 1