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_39812 ( "Year" real, "Mission type" text, "Shogun" text, "Ry\u016bky\u016ban King" text, "Lead Envoy" text, "Number in entourage" text )

### Question ###
What is the latest year of a gratitude type mission with 99 in the entourage?

### Accurate SQL ###

SELECT MAX("Year") FROM table_39812 WHERE "Number in entourage" = '99' AND "Mission type" = 'gratitude'