Question: Which Number of electorates (2009) has a District of jhajjar, and a Reserved for (sc/ST/None) of sc, and a Constituency number smaller than 66?
SQL: SELECT COUNT("Number of electorates (2009)") FROM "2-17922286-1" WHERE "District" = 'jhajjar' AND "Reserved for ( SC / ST /None)" = 'sc' AND "Constituency number" < 66.0;