Below is an context that describes a sql query, paired with an question that provides further information. Write an answer that appropriately completes the request.  # noqa: E501
### Context:
CREATE TABLE table_name_68 (year INTEGER, position VARCHAR, competition VARCHAR)
### Question:
What is the sum of Year(s), when Postion is 6th, and when Competition is Commonwealth Games?
### Answer:
SELECT SUM(year) FROM table_name_68 WHERE position = "6th" AND competition = "commonwealth games"