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_37610 ( "Date" text, "Opponent" text, "Score" text, "Loss" text, "Attendance" real, "Record" text )

### Question ###
What is the attendance of the game that has the opponent of The Nationals with a record of 68-51?

### Accurate SQL ###

SELECT SUM("Attendance") FROM table_37610 WHERE "Opponent" = 'nationals' AND "Record" = '68-51'