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_79104 ( "Year" real, "Theme" text, "Face Value" text, "Weight" text, "Diameter" text, "Mintage" real, "Issue Price" text )

### Question ###
What is the Year of the Coin with an Issue Price of $1089.95 and Mintage less than 900?

### Accurate SQL ###

SELECT SUM("Year") FROM table_79104 WHERE "Issue Price" = '$1089.95' AND "Mintage" < '900'