A new study of retail rents in Manhattan shows that the market's free fall may be more than just a market correction from an overheated peak.

Average asking rents across Manhattan retail spaces are at their lowest level in 17 years, according to a Real Estate Board of New York study as reported by the New York Post. The study confirms that rents have fallen too far to simply be a pendulum swing back from the 2014 peak, and may be indicative of a "retail apocalypse," according to a Post source.

The REBNY study found that 13 of the 17 corridors it tracks have lower average asking rents than they did in 2007. The hardest-hit retail corridor is in Greenwich Village, where rents on the stretch of Bleecker Street between Seventh Avenue South and Hudson Street declined by 25% year-over-year. Average asking rents there are $351/SF.

Also suffering severe setbacks is the fabled Madison Avenue between East 57th and East 72nd streets, where rents have dropped 27% since their 2014 peak of $1,709/SF. Broadway storefronts in SoHo have suffered a 34% drop over that same period.

The decline continues despite a significant increase in concessions from landlords doing their best to maintain rates, with more free rent and tenant improvement allowances being offered than ever before, according to the Post.

One shining exception to the trend is at the very top of the market, on Fifth Avenue between 49th and 60th streets — what the Post refers to as the city's Gold Coast. Average asking rents there are at an all-time high of $3,900/SF with solid occupancy rates. According to Cushman & Wakefield, it is currently the most expensive stretch of storefronts in the world, ahead of Hong Kong's Causeway Bay and London's Bond Street.

Just south of the priciest stretch of Fifth Avenue, occupancy is also stronger than in many other parts of Manhattan. Shoe retailer Vans recently signed a lease for a flagship store between 44th and 45th streets.