Pretty dramatic. The paper explores the reasons why, citing the economy, a general drop in play among all golfers, and more. But here's the nut sentence:
The Gabe Lozano course, on Old Brownsville Road, was closed for nearly eight months for improvements, and the Oso Beach course had sections closed throughout the past three years, Gavlik said.
When your two munis are inaccessible - at least in their full form - for eight months or three years at a time, of course the rounds are going to fall off a cliff. And rounds in Corpus have, dropping from a combined 140,000 (!) per year to "only" 80,000 per year. (It should be noted that the vast majority of golf courses in America would consider 40,000 rounds very heavy traffic; even for most municipals, that would be in line with norms.)
Whether the courses can make money going forward depends on getting them open and keeping them open. The quality of the renovations at Oso and Gabe's? Sure, that matters, but not as much as it would in larger cities. While golfers in Corpus have more options today than they did 10 years ago (mostly because of previously private clubs allowing public play on at least a limited basis), Oso and Gabe's are still the only games in town for muni golfers.