I generally find it useful to look at real rather than nominal returns, ie after inflation, which was about 24% over the past eight years. But still that would be a real capital appreciation return of about 4% per year.
That of course also reinforces your point about holding cash, which actually has a negative real return at the moment and that's not looking likely to change very soon.
In my view, predicting short term (ie up to three year) returns for any asset class is crystal ball gazing. But long term returns histories on the other hand are a very good guide. Over the past 50 years the real return premium for "risky" assets such as listed equities, over that for cash, has been about 4 per cent.
Over the past 35 years total returns from UK rental housing have been remarkably close to total returns from global equities (in sterling), and with significantly less volatility. So it has been a very good asset class to be in provided you don't need immediate liquidity and are rich enough to be able to hold several properties and so achieve some diversification. It has been skewed somewhat by the over-performance of London property during the period though, but even for rest-of-UK the typical returns have been attractive and will probably remain so - which is bad news for people without access to capital for a house to live in.