ก่อนปี 1990 มีกี่เกม ?ไม่จำเป็นต้องใช้ทุกโต๊ะ
how many games are there before 1990 ?It is not neccessary to use all the tables.
 table_204_121:  id [ number]  "year" [ text]  "game" [ text]  "developer" [ text]  "setting" [ text]  "platform" [ text]  "notes" [ text] 
SELECT COUNT("game") FROM table_204_121 WHERE "year" < 1990