Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_name_21 ( points VARCHAR, engine VARCHAR, year VARCHAR )

### Question ###
What is total amount of points of entrants with a ford cosworth engine and a year later than 1991?

### Accurate SQL ###

SELECT COUNT(points) FROM table_name_21 WHERE engine = "ford cosworth" AND year > 1991