Despite the gloomy economy in the region, there has been a massive construction boom by the Sacramento area's four big hospital groups. The expansion represents the largest ever in the Sacramento area for UC Davis Health System, Sutter Health, Catholic Healthcare West and Kaiser Permanente. Added together, they total more than 3.5 million square feet of construction and $2.6 billion in costs. Other than state government, healthcare was the only economic sector that grew in Sacramento's six-county region between February 2007 and February 2008.