AUSTIN -- Ninth-graders who failed Texas' new, tougher standardized tests the first time fared far better during retakes, state officials said Tuesday, a sliver of positive news for an exam regimen that has been roundly criticized in many educational quarters.Students took the State of Texas Assessments of Academic Readiness, or STAAR, exam for the first time last year, and are now required to pass 15 separate tests to graduate high school. STAAR is designed to be more rigorous than the statewide exam it is replacing, the Texas Assessment of Knowledge and Skills, but the new exam was so hard that nearly half of the ninth-graders who took the English I test didn't pass it. First-time passing rates were under 80 percent for the English I reading and world geography exams.However, students who retook those tests as 10th-graders this year saw their scores in all subject areas improve dramatically, according to Education Commissioner Michael Williams.The English I writing passing rate jumped from 54.4 percent last spring to 72.6 percent after retesting. English I reading jumped from 67.7 percent to 81.2 percent; world geography climbed to 84.8 percent from 79.7 percent; and 91 percent of students passed biology exams, up from 86.4 percent."The improvement in overall performance is directly attributable to the hard work of students and educators across our state," Williams said in a statement. "While there is still work to be done to ensure success for all, these improved numbers are indicative of what can occur when the focus is on students and a commitment to achieve success in the classroom."The Legislature created STAAR amid calls from leading business groups and others that Texas schools weren't doing enough to prepare students for the demanding jobs of tomorrow.State law requires that exam results count 15 percent toward students' final grades in core subjects, but the rule has been suspended the last two years.Also Tuesday, Williams released the last year's STAAR passing rates for students in grades three to eight for the first time. Those showed all grades passing the tests at rates above 70 percent. Eighth-graders scored the highest, with 80 percent passing the reading exam, 76 passing mathematics and 70 passing science.House Speaker Joe Straus and other key lawmakers have acknowledged the growing backlash against perceived "overtesting" of students. A series of bills before the Legislature would cut the number of STAAR exams high school students need to pass for graduation.