The Central Statistics Office has launched a revamped property price index. It is based on stamp duty returns rather than mortgage drawdown data and includes, for the first time, cash transactions, which are said to account for 50 per cent of property sales.

Here are the 10 most important things to know about it:

1. The national average house price in 2015 was €225,783.

2.The peak to trough fall in residential property prices was 54.4 per cent rather than 50.9 per cent as recorded previously.

3.Cash buyers generally paid less for residential property than mortgage buyers, all other things being equal, over the period 2010 to 2016.

4. In the year to July, residential prices at a national level increased by 6.7 per cent, compared with an increase of 4.9 per cent in June and an increase of 6.1 per cent recorded in the year to July 2015.

5.Apartment prices increased 7.4 per cent in the year to July.

6. Residential property prices are currently 34.7 per cent lower than at their highest level in April 2007.

7. The 12 months to July saw a drastic reverse in trend with a decrease of 1.7 per cent in the total number of purchases, compared to significant growth in the years to July 2013, 2014 and 2015 (34.1 per cent, 28.3 per cent and 35.1 per cent respectively).

8. The most expensive place nationwide to buy a house is the Dún Laoghaire-Rathdown area of Co Dublin where in 2015 buyers paid an average of €568,980.

9. The least expensive place to buy a house in 2015 was Co Longford, where the average price paid was just €79,660.

10. The difference in average spend between former owner-occupiers and first-time buyers has narrowed to just €51,405 on average, with former owner-occupiers paying more.