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_10 ( year_built VARCHAR, class VARCHAR, number VARCHAR )

### Question ###
What year was the class 253 larger than 18 built?

### Accurate SQL ###

SELECT year_built FROM table_name_10 WHERE class = "class 253" AND number > 18