Sorry; I was just working off the "5 billion coins a year" title.
I am just taking the number of new coins created in a year, and dividing it by the number of coins already in the money supply. So if Bitcoin was creating X bitcoins per year for the first four years, the inflation rate for year four was X / 3X = 33%. In year 5, they halved the reward rate, so the inflation rate for year 5 was X/2 / 4X = 12.5%, and for year 6 it was X/2 / (4X + X/2) = 11.1%.
If Dogecoin were minting a constant 5 billion coins per year, then the inflation rate is much simpler: it is always (100/N)%, which is the well-known harmonic series.
Accounting for the initial money supply of 100 billion Dogecoins, it basically just starts further down the harmonic series, and Dogecoin's inflation rate would be 100/(20+X)%, which looks like 5%, 4.8%, 4.5%, 4.3%, 4.2%...
I am just taking the number of new coins created in a year, and dividing it by the number of coins already in the money supply. So if Bitcoin was creating X bitcoins per year for the first four years, the inflation rate for year four was X / 3X = 33%. In year 5, they halved the reward rate, so the inflation rate for year 5 was X/2 / 4X = 12.5%, and for year 6 it was X/2 / (4X + X/2) = 11.1%.
If Dogecoin were minting a constant 5 billion coins per year, then the inflation rate is much simpler: it is always (100/N)%, which is the well-known harmonic series.
Accounting for the initial money supply of 100 billion Dogecoins, it basically just starts further down the harmonic series, and Dogecoin's inflation rate would be 100/(20+X)%, which looks like 5%, 4.8%, 4.5%, 4.3%, 4.2%...