Not raw data alas. What I have done as a crude proxy based upon data back to 1981:

- Monthly close of ASX200 (XJO). This data is pretty much everywhere and easy to get.

- Monthly data for the ASX200 accumulation index (XJOAI). This is harder to come by, but is available from the reserve bank stats page and a couple of other places

- For each month, work out the difference in percentage change between the two indices (this is the reinvested dividends, expressed as a monthly yield)

- Determine the payout by applying the yield to the XJO.

Using this approach, over this time period Australian dividends have grown significantly faster than inflation. However it is really volatile, and there are periods where dividends do fall in both real and nominal terms.

The other quick test is to look at the total data over the last 34.75 years (data from the RBA, table F7

http://www.rba.gov.au/statistics/tables/pdf/f07.pdf):

Total return

31 Dec 1979 XJOAI: = 1000

30 Sept 2014 XJOAI = 45717

Compound growth rate = 11.6%

Capital growth:

31 Dec 1979 XJO = 500

30 Sept 2014 XJO = 5293

Compound growth rate = 7%

i.e. over this period dividends averaged 4.6% = about the same yield as today! Dividend yield in 1980 was a touch under 5% (all these ignore franking credits, and the numbers are even better if we include them). If the yield is about the same, then dividends have been growing at about the same rate as the underlying securities, or about 7%.

Using CPI for inflation over the same period (we can argue about the relevance of CPI elsewhere) gets inflation of 425% over the same period, or if compounding over 34.75 years, about 4.25%. So, over this time period, dividends have grown in real terms (but not very smoothly).

This is why I'm reasonably comfortable with dividends increasing with inflation being a reasonably conservative assumption over the 60 years I'm investing for.

Keen to see alternate rationales for a different conclusion though.