Aunt Wang deposited 5000 yuan in the bank for six months, with an annual interest rate of 2.25%. The annual interest rate refers to the deposit interest rate for one year. The so-called interest rate is the abbreviation of interest rate, which refers to the ratio of interest amount to deposit principal or loan principal in a certain period of time. Usually divided into annual interest rate, monthly interest rate and daily interest rate. The annual interest rate is expressed as a percentage of the principal, the monthly interest rate as a percentage, and the daily interest rate as a percentage. When the economic development is in the growth stage, the investment opportunities of banks increase, the demand for loanable funds increases, and interest rates rise. On the other hand, when the economy is in a downturn and the society is in a depression, banks' willingness to invest will decrease, so will the demand for loanable funds, and the market interest rate will generally be lower.