CREATE TABLE table_13681_2 (equivalent_daily_inflation_rate VARCHAR(255), time_required_for_prices_to_double VARCHAR(255))
how many equivalent daily inflation rate with time required for prices to double being 3.7 days
    
SQL: SELECT COUNT(equivalent_daily_inflation_rate) FROM table_13681_2 WHERE time_required_for_prices_to_double = "3.7 days"