user: Question: What is the sum of low estimate(s) that is listed for the date of 1978?
Columns: ['Low Estimate', 'High Estimate', 'Type', 'Location', 'Date']
Types: ['real', 'real', 'text', 'text', 'text']
Sample row: [80000.0, 80400.0, 'Mass suicide, murder', 'Japan', '1945']
SQL:

assistant: SELECT SUM("Low Estimate") FROM "Table" WHERE "Date" = '1978';