Average Inflation rises in a fractional reserve system are tantamount to theft.
If you lent me 100 units of currency in year 1 and in year 5 I gave you 90 units back, you would not be happy at all. But when a government inflates at 2% a year, effectively that is what they do.
Problem with inflation measurements is they are not accurate or unbiased.
http://www.bbc.co.uk/news/business-28009477 - Deflation
http://www.bbc.co.uk/news/31559074 Inflation targeting