Is 2.5% of the total savings to be paid each year after its Hawl (one year) has passed, knowing that it is continuously growing, and is this action correct?

The hawl (one-year period) considered for the obligation of zakat is the Hijri year. Zakat becomes obligatory and must be disbursed when a complete year has passed over wealth that has reached the nisab (minimum threshold). As for wealth acquired during the year (benefited wealth), the zakat for each installment becomes due when its own hawl passes, according to the majority of scholars. However, it is permissible to pay the zakat for all wealth in advance when the hawl of the original capital is completed; this is easier and clears one's responsibility. Your desire to purchase land or a car with this wealth does not affect the obligation of zakat if the hawl has passed over the wealth while it is in your possession. Disbursing zakat in the first year does not exempt it from zakat in the second year.