CREATE TABLE table_204_909 (id NUMBER, "pollutant" CLOB, "units" CLOB, "emission standard" NUMBER, "coal-fired" CLOB, "petroleum coke-fired" CLOB)

what is the total number of pollutants that are measured with an lb/mmbtu unit ?
SELECT COUNT("pollutant") FROM table_204_909 WHERE "units" = 'lb/mmbtu'
SELECT COUNT("pollutant") FROM "table_204_909" WHERE "units" = 'lb/mmbtu'