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_74 (year INTEGER, opponent_in_the_final VARCHAR)
### Question:
How many years have an Opponent in the final of welby van horn?
### Answer:
SELECT SUM(year) FROM table_name_74 WHERE opponent_in_the_final = "welby van horn"