What amount at the end of the month would have to be saved by my parents until the end of my studies 1/09/2023 from the day of my birth 1/12/1999 to finance my studies at university assuming that the annual interest rate was on average 6% at the time of collecting funds, while during the payment period for studies decreases by 1 point percentage (from 6%) at the moment immediately after the payment of each installment. The calculations should be done for the actual provided date of birth 1/12/1999 and let's say the actual date of starting my studies at university is 1/10/2021 we assume that I pay for my studies the annual fee of 2200 euro by September 30 each year.