Surely any rate of growth should be calculated as compound inflation, rather than simple inflation?
This makes the year-on-year increase in the CASH fare 8.4%.
The year-on-year increase in the OYSTER fare is 4.3%.
As a comparison, the RPIX index (Retail Prices Index eXcluding mortgages) changed by an average of 3.0% over the period 1992 - 2011 (no data for 2012 is present, and since fares are now calculated on the basis of the previous year's RPI, that's not unreasonable)
There is still, quite clearly a disparity between other price changes and Z1 LU fares, but to blindly say 500% would be worthy of the "page 3" newspapers, and their deliberate statistical ignorance (anything for a good headline).
It should also be noted that I don't believe LU was always beholden unto inflationary-based rises in fares - was there not a period when they were expected to price according to demand (i.e., market-based pricing), thereby artificially raising the Z1 costs to price to the increased demand in Z1?
Finally, it should be noted that LU's cost bases do not necessarily follow general inflationary trends -- a lot of the equipment and materials they buy may not have seen the same inflation levels as consumer goods, as the cost of steel, concrete, specialist kit etc. may not have followed the general trends in clothing, food, consumer electronics and motor vehicles which have seen real-terms decreases in price in many cases.