AUSTIN, Texas (AP) — Texas on Wednesday issued its first letter grade academic accountability ratings for school districts, with only about 1 percent statewide receiving failing marks and about 10 times that getting 'As.'

The A-F rating scale has been hotly debated in the Republican-controlled Legislature for years and individual schools won't get grades until 2019, after state lawmakers postponed implementation under pressure from superintendents and school boards. Instead, campuses got numeric scores 0-100, as well as ratings ranging from "met standard" to "improvement required," with 4 percent of schools across Texas receiving failing "improvement required" designations.

The system evaluates the state's 1,200 public and charter districts on student achievement, school progress on things like statewide standardized testing and closing achievement gaps affecting low-income students. In all, 153 districts got an 'A' and 16 received 'Fs.'

Another 92 districts, or nearly 8 percent, would have received B, C, D or Fs but were exempted because of the effects of last summer's devastating Hurricane Harvey, according to the Texas Education Agency.

Education Commissioner Mike Morath noted that many A-rated districts were in economically disadvantaged areas, saying in a statement that, "Districts with high levels of poverty who attain this high level of performance are proof positive that poverty is not destiny."

Of the more than 8,700 campuses, including charters schools, rated Wednesday, 7,260, or nearly 96 percent, received "met standards" or completed alternative benchmark ratings. Those 293 schools receiving "improvement required" represented 4.3 percent of public districts, though another 86 campuses would have gotten "improvement required" but were exempted because of Harvey.

The A-F accountability system has been criticized by teacher groups and education advocates who worry that too many districts in poor areas will flunk, stigmatizing their students. Noel Candelaria, president of the Texas State Teachers Association, called the system "a misleading, incomplete way to gauge student success, and it was designed by the governor and the legislative majority to pass the blame for their own failures to children and educators."

But many top Texas conservatives counter that the system encourages academic rigor and is an easy way for parents to understand where districts stand. Its proponents include state Education Commissioner Michael Williams who said in statement: "Texas' new A-F accountability framework will kickstart the conversation around school quality by providing Texans with accurate, accessible, and actionable academic achievement data about schools and districts."

Florida implemented an A-F grade system in 1999. Around 20 states have since adopted similar ratings or are in the process of doing so.