Over the same comparative period we've seen our average lease term increase lease term increase by 34%. In some cases we're clearly investing higher NTI's but the spin is in sync with the level of credit and term. Office occupancy across our portfolio continues to outperform our markets by a substantial margin.
Overall, a solid operating performance in the face of a challenging economic environment which unfortunately is likely to persist well into 2011. We don't see fundamentals worsening but we remain uncertain as to when we'll see meaningful broad based improvement.
Turning to investment activity, during the third quarter we announced two deals totaling $110 million that should generate 9% plus average cash returns. This activity included the $53 million July acquisition of Crescent Center, a 336,000 square foot class A office building in Memphis. Subsequent to closing we've invested 1 million of the 2.3 million we earmarked for building improvements as we advertise the grounds and buildings.
In August, we won a $57 million builder suite headquarters to be constructed on the Country club plaza in Kansas City. This is a terrific opportunity for us to develop a class A 192,000 square foot building in a core infill location that will serve as the new headquarters for Polsinelli Shughart, a large and highly respected national law firm with more than 500 attorneys in 14 cities. This project is subjecting to resuming. When completed we will own or have an interest in 1.6 million square feet of office space in the Plaza submarket.We're also adding a second office project to our redevelopment pipeline, Highwood Center 2 in Atlanta. Earlier this month we signed a long term lease with the GSA for the entire building, 60,000 square feet for the U.S customs and border protection agency. This $11.5 million project will involve a substantial renovation and upgrade of the property is expected to generate an 8.5% stabilized cash return over the term. Read the rest of this transcript for free on seekingalpha.com