Andrea recently purchased a house and started furnishing it. 6 days after she purchased the house she had $2,750 in her bank account, but 22 days after she purchased the house she had $250 in her bank account. Let t represent the number of days since Andrea purchased her house and let b represent the corresponding amount of money Andrea has in her bank account (in dollars). From 5 days to 22 days after Andrea purchased her house, what was the change in t?