Overall, there has been an upward trend in the average prices of houses across all three countries. Notably, country A consistently had higher average house prices compared to B and C for most of the timeframe.
It is evident from the given data, the average property cost in Country A has witnessed significant changes. In 1997, it accounted to 0K, however by 2003, it had upsurged sharply to $510K. Although there was a slight decline of $80K in housing prices between 2003 and 2006, they steadily escalated until reaching their peak at $625K in 2014.
Moving further, in 1997, the average property price in countries B and C was estimated at $125,000. From 2005 to 2008, the average property price in country B dropped, but then the value reached at peak at approximately $500,000 by 2012. In contrast, country C's prices experienced a decline until 2008, followed by consistent growth until 2013 and a slight reduction to approximately $260,000 at the end of the period.