This year's MFE Concept Community survey gauged the housing wants and needs of more than 84,000 renters nationwide, our largest total ever.

In this week's installment about facts and figures from the survey, which spanned all age ranges, we look at certain common-area fitness amenities for which renters are most willing to pay extra. While pools and fitness centers are somewhat expected, the focus here is on the unconventional amenities that renters don't see in most communities. Below, we zero in on what Gen Y, specifically, values most.

We asked about the desirability of yoga rooms, golf simulators, spin cycle studios, fitness machines with Bluetooth connectivity, among many other items. Three unconventional amenities stood out from the pack as offering owners the highest rent premiums: fitness instruction classes, steam rooms, and walking trails.

Fitness instruction classes emerged as the most in-demand unconventional amenity, with 46% of renters willing to pay extra for them. Roughly 18% of renters were willing to pay $5 extra per month, and 14% were willing to pay $10. Another 14% indicated they would go up to at least $15 more per month to have the option of taking fitness classes.

Demographically, millennials were most likely to pay extra, with more than half indicating it was worth an extra sum. Gen X wasn't far behind, at 43%. Surprisingly for this cost-conscious demographic, 16% of millennials indicated they'd be willing to pay at least $15 extra per month for fitness classes.

The next stop after a fitness class would be a steam room, which emerged as the second-most desirable amenity for which renters would pay extra, at 43%. Nearly 20% of all renters indicated they'd pay $5 more per month for a steam room, while another 12% would pay $10 and yet another 12% indicated that such an amenity was worth at least $15 more per month.

Demographically, millennials were once again the most anxious for a steam room, with 21% willing to chip in $5 more per month, and 13% suggesting they'd go as high as $10, with another 13% valuing it at $15 or more per month.

Finally, walking trails/tracks emerged as the third-most desired unconventional amenity, with 42% of renters willing to run up their rents by a little extra every month. In fact, nearly a quarter (24%) of all renters would pay at least $10 extra per month for access to a walking trail or track.

Demographically, once again, millennials were most excited by the prospect. Unexpectedly, more millennials would pay more than $15 per month (15%) for access to a track or walking trail than would pay $10 extra (13%), underscoring how desirable this amenity is. Nearly 20% of millennials would at least tack on $5 for the privilege.

The full results of our groundbreaking survey, The Next-Gen Apartment: What Renters Want, done in conjunction with J Turner Research, will be unveiled at the Multifamily Executive Conference in September.

In the meantime, check out our previous 2016 MFE Concept Community Stats of the Week: