At the end of Q1 this year, our operating portfolio occupancy was 89.1%, an increase of 0.5% from last quarter and down only 0.6% from a year ago.
During Q1, our collections remains strong approximately 95% of our rents for the quarter and for the month of April.
Our new lease count was 46 in the quarter, significantly higher than last quarter's count of 28 and our total lease count was 94, 12% higher than the previous quarter.
Our blended leasing spread was 7.8%, 1 full percentage point higher than last quarter 6.8%.
And our same-store net operating increase -- decrease 4.3% was flat last quarter yet among the best in the industry.
Additionally, in Q1 we increased our quarterly dividend by 2.4% and have paid a monthly dividend to our shareholders for 120 consecutive months.
They drive 18 hour traffic, 7 days a week to our properties.
A reminder of shareholder that Whitestone was built during the recession of 2008 to 2010 and many of the lessons that we learned during we incorporated into the fiber of the company.
By providing annual rent increases of 2% to 3%, while passage through triple net expenses and by keeping our focus on training and developing our people for for continuity.
Our swift response to COVID-19 12 months ago strengthened our balance sheet liquidity and financial flexibility to successfully navigate economic impacts of the pandemic.
This acquisition will add just under 200,000 square feet and would be immediately accreted to Whitestone's FFO per share and positively contribute to Whitestone's long-term goals related to debt, leverage and G&A coverage.
Our leasing activity in the quarter was very strong with 46 new leases, representing 117,000 square feet of newly occupied spaces.
This level of new lease square footage was 90% higher than our average quarterly lease volume for the previous three year period.
And 21% higher than the highest quarter over the past three years.
On a total lease value basis, this quarter was more than double our average quarterly lease volume for the previous three year period and 38% higher than the highest quarter over the past three years.
Regarding occupancy, our operating portfolio occupancy stood at 89.1%, up 1.5% from the fourth quarter and down only 6 -- 0.6% from a year ago with our Austin market leading the way with almost 4% increase in occupancy from Q4.
Leasing spreads on a GAAP basis have been positive 9% over the last 12 months, and first quarter leasing spreads increased 5.3% on new leases and 9.6% on renewal leases signed.
Our annualized base rent per square foot on a GAAP basis at the end of the quarter grew 1% to $19.71, from $19.58 in the previous quarter, and basically in line with our pre-COVID ABR from a year ago.
Funds from operations core was $0.23 per share in Q1, compared to $0.24 per share in the prior year.
As Jim, mentioned our collection continued to trend toward normal pre-COVID levels, with 95% of our contractual rents collected in Q1.
Restaurants and food service, our largest tenant category, which represents 23% of our ABR and 17% of our leases square footage continued to perform very well, staying 95% in the quarter and we also saw positive movements in some of our impacted customer types, with entertainment representing only 2% of our ABR, and leased square footage paying 73% of their rents in the quarter, up from 48% in Q4.
During the quarter we had minimal rent deferrals, representing 45% of our total contractual billings.
Our same-store net operating income was down 4.3% for the quarter versus the prior year quarter, and we expect our same-store growth to resume as we move throughout the balance of the year and into 2022.
Reflecting the continued improvement in the portfolio, our reserve for uncollectible revenue was $529,000 or 1.8% of revenue, down from 4% of revenue in Q4.
To put this in further perspective, our first quarter reserve equates to only 9% of 2020s full year reserves.
Our interest expense was 8% lower than a year ago, reflecting $15 million in lower average debt, and a decrease in our overall interest rate from 3.9% to 3.6%.
Included on Page 27 of our soft data is a breakdown of our tenants by type.
All of our credit category were above 89% collection in Q1, with the exception of entertainment, which I previously discussed.
Our three largest categories, restaurants, grocery and financial services were at 95%, 100% and 99% respectively.
At quarter end, we had $23.3 million in accrued rents and accounts receivable, included in this amount is $16.9 million of accrued straight-line rents, and $1.8 million of agreed upon deferrals.
Our agreed upon deferral balance is down 18% from year end, reflecting tenants honoring their payment plans.
Our total net debt is $632 million, down $17 million from a year ago, and our liquidity representing cash and availability on our corporate credit facility, stands at $39 million at quarter end.
During April, we paid down an additional $10 million of our corporate credit facility.
Currently, we have a $140.5 million of undrawn capacity, and $25.9 million of borrowing availability under our credit facility.

Summary:
Funds from operations core was $0.23 per share in Q1, compared to $0.24 per share in the prior year.