how many times was fus/refus 2-3 vertebrae performed until 2103?
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 = 'fus/refus 2-3 vertebrae' ) and strftime('%y',procedures_icd.charttime) <= '2103'