NEW YORK (Reuters) - The sale price of high-end condominiums in Manhattan’s most expensive neighborhood averaged $14.1 million in the 12 months through June, with one unit going for $65.7 million, data from a New York realty company showed on Tuesday.

Construction is seen in the Hudson Yards area of the West Side of Manhattan in New York U.S., November 21, 2016. Picture taken November 21, 2016. REUTERS/Shannon Stapleton

The unit, at 432 Park Avenue, billed as the tallest residential tower in the Americas, was one of three at the Midtown East building that were in the top-five most expensive condominium sales in Manhattan, an analysis by CityRealty said.

The analysis examined sale prices and what was paid per square foot in an index the realty company has created to gauge investment performance for what it considers the top 100 condominium buildings in Manhattan.

The average price per square foot rose 9 percent to $2,788 in the 12-month period ended June 30, while the number of units sold, or sales volume, dipped 3 percent to 1,098, a report based on CityRealty’s 100 index said.

CityRealty compiles the data to examine how prime Manhattan real estate performs, as it is considered a good investment when larger market forces are not at work, said Gabby Warshawer, research director at CityRealty.

Over the past 10 years, the CityRealty 100 index has grown a compounded 3.4 percent a year, while the spot price for a barrel of West Texas Intermediate oil over the same period has fallen 3.9 percent and the S&P 500 index has risen 2.2 percent.

Spot gold prices have risen 6.8 percent a year during the period, the report said.

“We expect (Manhattan realty) prices to increase year over year. Nine percent is quite a healthy increase. It’s not wild, but it shows that there’s quite a bit of buyer demand for these buildings in the index,” Warshawer said.

Prices for buildings in the index rose in part because of closings recorded in very expensive newer developments, such as 432 Park Avenue and One57 on 57th Street, as well as continued high prices in properties such as 15 Central Park West.

The highest price per square foot paid for a condominium was $9,581 a square foot at 15 Central Park West, a building that garnered the top three most expensive sales by square feet.

There are 14,224 units in the CityRealty 100 index and the average sale price was $6.5 million for the units sold. The average sale price is expected to rise to $7.4 million next year, CityRealty said.