instruction: how many times has remove skull tongs procedure been done until 2104?
response: 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 = 'remove skull tongs') AND STRFTIME('%y', procedures_icd.charttime) <= '2104'