CREATE TABLE Rating (rID NUMBER, mID NUMBER, stars NUMBER, ratingDate DATE)
CREATE TABLE Movie (mID NUMBER, title CLOB, year NUMBER, director CLOB)
CREATE TABLE Reviewer (rID NUMBER, name CLOB)

For directors who had more than one movie, bin the year into Year interval and them compute the total number of movies in each year bucket, and group by title The result can be drawn as a trend line, and display in ascending by the x-axis.
SELECT year, COUNT(year) FROM Movie AS T1 JOIN Movie AS T2 ON T1.director = T2.director WHERE T1.title <> T2.title GROUP BY title ORDER BY year
SELECT "year", COUNT("year") FROM "Movie" "T1" JOIN "Movie" "T2" ON "T1"."director" = "T2"."director" AND "T1"."title" <> "T2"."title" GROUP BY "title" ORDER BY "year"