ขั้นตอนการถอดแหนบกะโหลกออกกี่ครั้งแล้วจนถึงปี 2104?ไม่จำเป็นต้องใช้โต๊ะทั้งหมด
how many times has remove skull tongs procedure been done until 2104?It is not neccessary to use all the tables.
 d_icd_diagnoses:  row_id [ number]  icd9_code [ text]  short_title [ text]  long_title [ text] 
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'