CREATE TABLE table_203_457 (id NUMBER, "tramway" CLOB, "country" CLOB, "city" CLOB, "height of pylons" CLOB, "span width , \ leaning straight line" CLOB, "span width , \ horizontal measurement" CLOB, "height of cable over ground" CLOB, "year of inauguration" NUMBER, "notes" CLOB)

at least how many aerial tramways were inaugurated after 1970 ?
SELECT COUNT("tramway") FROM table_203_457 WHERE "year of inauguration" > 1970
SELECT COUNT("tramway") FROM "table_203_457" WHERE "year of inauguration" > 1970