CREATE TABLE table_2572 ("Sigma level" FLOAT, "Sigma  ( with 1.5\\u03c3 shift ) " CLOB, "DPMO" CLOB, "Percent defective" CLOB, "Percentage yield" CLOB, "Short-term C pk" CLOB, "Long-term C pk" CLOB)

How many percentage yield figures are there when 6.7% are defective?
SELECT COUNT("Percentage yield") FROM table_2572 WHERE "Percent defective" = '6.7%'
SELECT COUNT("Percentage yield") FROM "table_2572" WHERE "Percent defective" = '6.7%'