As announced in the 2016–2017 Federal Budget, the Government has proposed a lifetime non-concessional superannuation contributions cap of $500,000 to apply from Budget night (3 May 2016). This means that people who are planning to make non-concessional contributions now need to check their historical non-concessional contributions data back to 1 July 2007 (which will be counted against the $500,000 lifetime limit).
To this end, the ATO can calculate non-concessional contribution amounts for the period 1 July 2007 to 30 June 2015, provided that the individuals and funds have met their lodgment obligations.
The ATO can only calculate the amount of non-concessional contributions based on the information it has. It may be prudent to review your own history of contributions.