Both same-store and non-same-store assets are performing well, with lease-ups particularly in non-same-store assets outpacing our projections as NOI grew by 46%.
With the addition of the recently announced ezStorage portfolio, our year-to-date 2020 acquisition activity either closed or under contract is $2.5 billion.
Of note, since 2019, we have acquired, developed and redeveloped approximately 22 million square feet and have expanded our portfolio by 13% having invested $4.3 billion.
First, the integration of the assets into the Public Storage brand and operating platform will be seamless as we already had a broad presence in these markets with 115 assets.
We now enjoy even stronger presence with now 163 assets with unmatched brand presence across the Mid-Atlantic region.
The Public Storage development team has taken lead on these opportunities and is ready to execute on each one of them, allowing us to expand the portfolio by approximately 10% over the next 24 months.
Looking to fall 2021, we are encouraged by core customer demand, our well located portfolio, the strength of our balance sheet and the quality and dedication of the 5,000 plus team members at Public Storage, all of whom are committed to enhancing the leading brand in the self-storage industry.
In the same-store, our revenue increased 3.4% compared to the first quarter of 2020, which represents a sequential improvement in growth of 2.6% from the fourth quarter.
The benefit this quarter was worth $0.05 of FFO.
Some of the technology and operating model evolution we'll discuss on Monday at our Investor Day showed up in our first quarter numbers with property payroll down 13% in the quarter given efficiency improvements.
And as we started 2021, we've seen continued strength, as Joe mentioned, in customer demand with occupancy is up 260 basis points and in-place contract rent per occupied square foot turning into positive year-over-year territory in January.
We anticipate same-store revenue to grow from 4% to 5.5% in 2021.
Our current expectations are for occupancy to be down 100 basis points plus in the fourth quarter compared to 2020.
Our expectations are for 1% to 2% same-store expense growth.
Property tax expense growth will pick up this year with our expectations around a 5% increase for the year, again recognized ratably through the year.
In total, our outlook is for core FFO per share of $11.35 to $11.75 for 2021.
The offering comprised of three, seven and 10 year tranches with the weighted average cost of about 1.6%.

Summary:
In total, our outlook is for core FFO per share of $11.35 to $11.75 for 2021.