It should be a negative, just as the value of consumables are over time. But that's not possible in a system heavily indebted and addicted to interest rates under the free market rate (only possible because banks create money effortlessly and hold it artificially low to enable a monopoly on "debt"). Such a policy would quickly collapse the current system as the value of the debt would increase over time instead of decrease, and so instead the banks inflate the value of the currency down to 0 which takes more time for the system to collapse (which fiat currencies always do and always will).

Starting again with a hard money, we would thrive, instead of being enslaved by a system that continuously stealthily, steals the value out of the fruits of our labour (at a rate of ~7% year) and gives it to the bankers and those closest to them.