When I first started with Extra Space, we had 12 stores and it's incredible to see the exceptional growth of this company, the value we've created for our shareholders.
Same-store occupancy set another new high watermark at the end of June at 97%, which is incredible, as you consider the diversification of our national portfolio.
The elevated occupancy led to exceptional pricing power with achieved rates to new customers in the quarter over 60% higher than 2020 levels.
While this is inflated by an artificially low prior year comp, achieve rates were over 30% greater than 2019 levels and accelerated through the quarter.
Other income is no longer a drag on revenue due to late fees improving year-over-year and actually contributed 20 basis points to revenue growth in the quarter.
These drivers produced same-store revenue growth of 13.6%, a 900 basis point acceleration from Q1, and same-store NOI growth of 20.2%, an acceleration of over 1,300 basis points.
In addition, our external growth initiatives produced steady returns outside of the same-store pool, resulting in FFO growth of 33.3%.
Given the pricing we are seeing in the market, we have listed an additional 17 stores for outright disposition, which we expect to close during the back half of 2021.
Year-to-date, we have been able to close or put under contract acquisitions totaling $400 million of Extra Space investment.
We have increased our 2021 acquisition guidance to $500 million in Extra Space investments.
We were active on the third-party management front, adding 39 stores in the quarter and a total of 100 stores through the first six months.
In the quarter, we purchased 11 of these stores in the REIT or in one of our joint ventures.
Our first half outperformance coupled with steady external growth and the improved outlook for the second half of 2021 allowed us to increase our annual FFO guidance by $0.50 or 8.3% at the midpoint.
While we still assume a seasonal occupancy moderation of approximately 300 basis points from this summer's peak to the winter trough, the moderation will begin from a higher starting point than we previously expected.
Core FFO for the quarter was $1.64 per share, a year-over-year increase of 33.3%.
Despite property tax increases of 6%, we delivered a reduction in same-store expenses in the quarter.
These increases were offset primarily by 13% savings in payroll and 31% savings in marketing.
In May, we completed our inaugural investment-grade public bond offering, issuing $450 million in 10-year bonds at 2.55%.
Our quarter end net debt-to-EBITDA was 4.8 times, giving us significant dry powder for investment opportunities since we generally target a range of 5.5 to 6 times on this metric.
We raised our same-store revenue range to 10% to 11%.
Same-store expense growth was reduced to 0% to 1%, resulting in same-store NOI growth of 13.5% to 15.5%, a 750 basis point increase at the midpoint.
We raised our full year core FFO range to be $6.45 to $6.60 per share, a $0.50 or 8.3% increase at the midpoint.
Due to stronger lease-up performance, we dropped our anticipated dilution from value-add acquisitions and C of O stores from $0.14 to $0.12.

Summary:
Core FFO for the quarter was $1.64 per share, a year-over-year increase of 33.3%.
We raised our full year core FFO range to be $6.45 to $6.60 per share, a $0.50 or 8.3% increase at the midpoint.