Among the cars produced in year 1973, how many of the cars have horsepower less than 100?
produced in year 1973 refers to model_year = 1973; have horsepower less than 100 refers to horsepower < 100
SELECT COUNT(*) FROM data AS T1 INNER JOIN production AS T2 ON T1.ID = T2.ID WHERE T2.model_year = 1973 AND T1.horsepower < 100
database name:db_id cars
country table country Cols: origin dtype integer, country dtype text, 
price table price Cols: ID dtype integer, price dtype real, 
data table data Cols: ID dtype integer, mileage per gallon dtype real, number of cylinders dtype integer, displacement dtype real, horse power dtype integer, weight dtype integer, acceleration dtype real, model dtype integer, car name dtype text, 
production table production Cols: ID dtype integer, model year dtype integer, country dtype integer, 
