[INST] Here is a database schema:
customers :
CustomerID [ INTEGER ] primary_key
Segment [ TEXT ]
Currency [ TEXT ]

gasstations :
GasStationID [ INTEGER ] primary_key
ChainID [ INTEGER ]
Country [ TEXT ]
Segment [ TEXT ]

products :
ProductID [ INTEGER ] primary_key
Description [ TEXT ]

transactions_1k :
TransactionID [ INTEGER ] primary_key
Date [ DATE ]
Time [ TEXT ]
CustomerID [ INTEGER ]
CardID [ INTEGER ]
GasStationID [ INTEGER ]
ProductID [ INTEGER ]
Amount [ INTEGER ]
Price [ REAL ]

yearmonth :
CustomerID [ INTEGER ] yearmonth.CustomerID = customers.CustomerID
Date [ TEXT ]
Consumption [ REAL ]

Please write me a SQL statement that answers the following question: For the customer who paid 634.8 in 2012/8/25, what was the consumption decrease rate from Year 2012 to 2013? [/INST]
SELECT CAST(SUM(IIF(SUBSTRING(Date, 1, 4) = '2012', Consumption, 0)) - SUM(IIF(SUBSTRING(Date, 1, 4) = '2013', Consumption, 0)) AS FLOAT) / SUM(IIF(SUBSTRING(Date, 1, 4) = '2012', Consumption, 0)) FROM yearmonth WHERE CustomerID = ( SELECT T1.CustomerID FROM transactions_1k AS T1 INNER JOIN gasstations AS T2 ON T1.GasStationID = T2.GasStationID WHERE T1.Date = '2012-08-25' AND T1.Price = 634.8 );