CREATE TABLE table_6170 ("Year" FLOAT, "Total Convictions" FLOAT, "Homicide  ( Art. 111 , 112 , 113 , 116 StGB ) " FLOAT, "Serious Bodily Injury  ( Art. 122 StGB ) " FLOAT, "Minor Bodily Injury  ( Art. 123 StGB ) " FLOAT, "Sexual Contact with Children  ( Art. 187 StGB ) " FLOAT, "Rape  ( Art. 190 StGB ) " FLOAT, "Theft  ( Art. 139 StGB ) " FLOAT, "Robbery  ( Art. 140 StGB ) " FLOAT, "Receiving Stolen Goods  ( Art. 160 StGB ) " FLOAT, "Embezzlement  ( Art. 138 StGB ) " FLOAT, "Fraud  ( Art. 146 StGB ) " FLOAT, "Narcotics Possession" FLOAT, "Major Violation of Traffic Laws  ( Art. 90 SVG ) " FLOAT, "Drunk Driving  ( Art. 91 Abs. 1 Satz 2 SVG ) " FLOAT)

Which year earlier than 2006 has the average Total Convictions of Fraud at 1,521?
SELECT AVG("Total Convictions") FROM table_6170 WHERE "Fraud (Art. 146 StGB)" = '1,521' AND "Year" < '2006'
SELECT AVG("Total Convictions") FROM "table_6170" WHERE "Fraud (Art. 146 StGB)" = '1,521' AND "Year" < '2006'