how many other appendectomy procedures were carried out since 2 years ago?
select count(*) from procedures_icd where procedures_icd.icd9_code = ( select d_icd_procedures.icd9_code from d_icd_procedures where d_icd_procedures.short_title = 'other appendectomy' ) and datetime(procedures_icd.charttime) >= datetime(current_time,'-2 year')