It should be noted that the post-High Line sales regression lines have been shifted for better visualization.  The actual lines (dotted lines) for both mean and median price comparison were shifted down compared to the pre-High Line sales regression lines. This is because the opening of High Line coincided with the time of the great recession. The housing prices were impacted by the recession and the sale prices just started picking up the trend in the beginning of post-High Line period. In order to minimize the effect of recession on the sale prices, we decomposed the sale price time series corresponding to the period before recession (before July 2007) using fast Fourier transform and extrapolated the result to predict the monthly sales pattern until December 2016. We then compared our extrapolation with the actual sale prices.