Use it to compare historic value of Taka with current values.
Note : A person earning 3000 in 1980 is equivalent to earning 30,000 now in 2020.
As Dollar was vallued Tk30/dollar and purchasing power of dollar in 1980 was 3.16.
Currently 1 dollar is 90 bdt.
And my first job in 1994 is equivalent to 2.5x times the salary amount in current value.