when is the last time in 2103 that patient 6440 received incision of chest wall?
select procedures_icd.charttime from procedures_icd where procedures_icd.icd9_code = ( select d_icd_procedures.icd9_code from d_icd_procedures where d_icd_procedures.short_title = 'incision of chest wall' ) and procedures_icd.hadm_id in ( select admissions.hadm_id from admissions where admissions.subject_id = 6440 ) and strftime('%y',procedures_icd.charttime) = '2103' order by procedures_icd.charttime desc limit 1