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_69484 ( "Low Estimate" real, "High Estimate" real, "Type" text, "Location" text, "Date" text )

### Question ###
What is the sum of low estimate(s) that is listed for the date of 1978?

### Accurate SQL ###

SELECT SUM("Low Estimate") FROM table_69484 WHERE "Date" = '1978'