Table: rohtak_lsb
Columns: constituency_number
name
reserved_for_sc_st_none
district
number_of_electorates_2009

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 rohtak_lsb WHERE "district" = 'jhajjar' AND "reserved_for_sc_st_none" = 'sc' AND "constituency_number" < 66