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_27 (year_of_most_recent_appearance INTEGER, year_of_first_appearance VARCHAR, corps_name VARCHAR)

### Question ###
What is the average year of the most recent appearance of the Boston Crusaders, who had their first appearance after 1976?

### Accurate SQL ###

SELECT AVG(year_of_most_recent_appearance) FROM table_name_27 WHERE year_of_first_appearance > 1976 AND corps_name = "boston crusaders"