Growing the portfolio from 77% of ABR from grocery-anchored properties to 85% plus remains a strategic focus across the organization.
During the fourth quarter, we executed 92 new leases, totaling 406,000 square feet, which exceeded the amount achieved in the fourth quarter of 2019.
At that point, new leasing spreads remained positive, rising 6.8% during the fourth quarter.
We are focused on the highest and best use of our real estate and believe the 80-20 rule applies to our assets and gives us tremendous flexibility and adaptability to create value in the future through our entitlement initiatives.
Specifically, 80% of our real estate consists of parking lots, that are not generating any revenue; and 20%, the single-storey buildings.
Target also stated that more than 95% of sales are fulfilled by the stores.
The overall transaction volumes from March through year-end were down close to 85%, but there were several late 2020 deals that showcased the general theme we have seen occurring.
Multiple grocery-anchored deals have transacted at sub 6% cap rates in Denver, South Florida, California, Washington DC, North Carolina and throughout the major primary and secondary markets in the U.S. While we are bullish on that asset side, which represents the core products within our portfolio, there is no shortage of capital chasing those deals.
A $25 million mezzanine financing on a strong South Florida shopping center and a $10 million preferred equity investment on a densely located center in Queens, New York; both of which will generate an accretive return versus our cost of capital, with a chance to possibly acquire in the future.
To that point, we completed a sale leaseback transaction in which we acquired two Rite Aid distribution centers in California for approximately $85 million.
These distribution centers service all 540 plus stores for the pharmacy chain in the State of California.
For the fourth quarter 2020, NAREIT FFO was $133 million or $0.31 per diluted share as compared to $151.9 million or $0.36 per diluted share for the fourth quarter 2019.
The reduction was mainly due to rent abatements and increased credit loss of $21.2 million and lower net recovery from a $5.7 million.
This reduction was offset by lower preferred dividends of $3.1 million and a $7.2 million charge for the redemption of preferred stock in the fourth quarter of 2019.
Now, although not included in NAREIT FFO, during the fourth quarter 2020, we did record a $150.1 million unrealized gain on the mark-to-market of our marketable securities, which was primarily driven by the change in value of our $39.8 million shares of Albertsons stock.
Our stake in Albertsons is valued in excess of $650 million today.
For the full year 2020, NAREIT FFO was $503.7 million or $1.17 per diluted share as compared to $608.4 million or $1.44 per diluted share for the prior year.
The change was primarily due to increases in rent abatements, credit loss and straight line reserves, aggregating $105.8 million and the NOI impact of disposition activity during 2019 and 2020 totaling $24.7 million.
In addition, during 2020, we incurred a $7.5 million charge for the early extinguishment of debt.
These reductions were offset by lower financing costs of $15.7 million and an $18.5 million charge for the redemption of $575 million of preferred stock during 2019.
All our shopping centers remain open, and over 97% of our tenants are open and operating.
We collected 92% of fourth quarter base rents, and this compares to third quarter collections of 90%.
The furloughs granted during the fourth quarter were just under 2%, down from 5% during the third quarter.
At year-end 2020, 8.2% of our annual base rents were from tenants on a cash basis of accounting.
And 50% of that has been collected.
As of year-end, our total uncollectible reserve was $80.1 million or 46% of our total pro rata share of outstanding accounts receivable.
We finished the fourth quarter with consolidated net debt to EBITDA of 7.1 times.
And on a look-through basis, including pro rata share of JV debt and preferred stock outstanding, the level was 7.9 times.
This represents further progress from the 7.6 times and 8.5 times levels reported last quarter, with the improvement attributable to lower credit loss.
On a pro forma basis, if our Albertsons investment was converted to cash, these metrics would improve by a full turn to 6.1 times and 7 times respectively.
We ended 2020 with a strong liquidity position, comprised of over $290 million in cash and $2 billion available on our untapped revolving credit facility.
We have only $140 million of consolidated mortgage debt maturing during 2021.
Our consolidated weighted average debt maturity profile stood at 10.9 years, one of the longest in the REIT industry.
By way of example, our 10-year green bond issued in July 2020 at 210 basis points over the 10-year treasury is currently trading in the area of 90 basis points over treasury.
Regarding our common dividend, we paid a fourth quarter 2020 common dividend of $0.16 per share.
Our initial NAREIT FFO per share guidance range is $1.18 to $1.24.
Notwithstanding the expected optics of the first quarter results, our NAREIT FFO per share guidance range of $1.18 to $1.24 reflects growth over 2020 at both the low and high end of the range.

Summary:
For the fourth quarter 2020, NAREIT FFO was $133 million or $0.31 per diluted share as compared to $151.9 million or $0.36 per diluted share for the fourth quarter 2019.
Our initial NAREIT FFO per share guidance range is $1.18 to $1.24.
Notwithstanding the expected optics of the first quarter results, our NAREIT FFO per share guidance range of $1.18 to $1.24 reflects growth over 2020 at both the low and high end of the range.