Get rows where price decreased compared to the previous date
petrol_details (pump, products, price, date)?
[
(PUMP-1, Petrol, 100.05, 2025-01-01),
(PUMP-1, Petrol, 98.00, 2025-01-02 ),
(PUMP-1, Diesel, 90.00. 2025-01-01 ),
(PUMP-1, Diesel, 95.00, 2025-01-02 ),
(PUMP-2, Petrol, 101.05, 2025-01-01),
(PUMP-2, Petrol, 97.99, 2025-01-02 ),
(PUMP-2, Diesel, 90.05. 2025-01-01 ),
(PUMP-2, Diesel, 86.00, 2025-01-02 )]