With this strong demand, we achieved average quarterly occupancy that was 420 basis points higher than last year.
We grew occupancy 170 basis points during the second quarter.
This has allowed us to be more aggressive with rates, which has helped to drive an increase in net effective rates by more than 50% through the end of June.
The vast majority of our acquisitions were off market, including 13 stores from our third-party management portfolio through the first half of 2021.
We closed on a record $534 million of wholly owned acquisitions through the first half of this year, already matching our total acquisition volume of last year.
These acquisitions are expected to generate a blended year one cap rate of 4.5% and represent a nice mix of markets and maturity with almost one-third in lease-up and roughly 70% in the Sunbelt region.
In addition to $22 million of closed acquisition subsequent to the quarter end as well as an additional $80 million currently under contract, we have a strong late-stage pipeline of attractive opportunities that our team continues to work on.
Our third-party management portfolio totaled 340 stores at quarter end and we added 19 more stores in July as owners and developers are attracted to our operating performance and innovative technology platforms.
Including rental income associated with these business customers, Warehouse Anywhere's year-to-date revenue is up almost 30% to a $14 million run rate including $9 million of annualized fee income.
We have increased the midpoint of our estimated adjusted funds from operations per share 8.5% to $4.74 this year, which would be 19.4% growth over 2020.
Last night, we reported adjusted quarterly funds from operations of $1.20 per share for the second quarter, an increase of 27.7% over the same period last year.
Second quarter same-store revenue accelerated significantly to 14.7% year-over-year, more than double the 7.3% growth produced in the first quarter.
Revenue performance was driven by a 420 basis-point increase in same-store average quarterly occupancy.
In the quarter, our same-store move-ins were paying almost 16% more than our move-outs.
This pricing power, along with our ability to push rates on existing customers, contributed to an 8.3% year-over-year growth of same-store in-place rates for the second quarter, up from just 1.3% growth in the first quarter of this year.
Discounts as a percentage of same-store rental revenue declined 60% year-over-year to 1.4% in the quarter.
Same-store operating expenses grew only 3.9% year-over-year for the quarter.
The increases were partially offset by an 11% decrease in Internet marketing expenses.
The net effect of the same-store revenue and expense performance was a 320 basis-point expansion in our net operating income margin resulting in 20.2% year-over-year growth in same-store NOI for the second quarter.
We supported our acquisition activity and liquidity position by issuing approximately $148 million of common stocks via our ATM program in the second quarter.
Our net debt to recurring EBITDA ratio decreased to 5 times, and our debt service coverage increased to a healthy 5.3 times at June 30th.
At quarter end, we had $360 million available on our line of credit, and we have no significant debt maturities until April of 2024 when $175 million becomes due.
Our average debt maturity is 6.2 years.
Specifically, we expect same-store revenue to grow between 10.5% and 11.5%.
Excluding property taxes, we continue to expect other expenses to increase between 2.25% and 3.25%, while property taxes are expected to increase 6.75% to 7.75%.
The cumulative effect of these assumptions should result in 13.5% to 14.5% growth in same-store NOI.
We have also increased our anticipated acquisitions by $325 million to between $800 million and $1 billion.
Based on these assumption changes, we anticipate adjusted FFO per share for 2021 year to be between $4.69 and $4.79.

Summary:
Last night, we reported adjusted quarterly funds from operations of $1.20 per share for the second quarter, an increase of 27.7% over the same period last year.