CREATE TABLE table_203_506 (id DECIMAL, "opponent" TEXT, "played" DECIMAL, "won" DECIMAL, "lost" DECIMAL, "drawn" DECIMAL, "% won overall" TEXT)

for how many teams was the win percentage below 90 %
SELECT COUNT("opponent") FROM table_203_506 WHERE "% won overall" < 90
SELECT COUNT("opponent") FROM "table_203_506" WHERE "% won overall" < 90