Texas Gov. Rick Perry on Monday proposed a four-year tuition freeze for incoming college freshmen and suggested that some of the money the state spends on schools should be tied to the number of students they graduate.  Perry, who announced his education priorities during a news conference at a Dallas high school, also called on schools to give families a better understanding of the amount of money they'll spend on college, depending on how long it takes the student to graduate.  Perry challenged universities last year to come up with $10,000 or less bachelor's degrees and he said that so far, nine institutions in Texas currently offer or have announced plans for such degrees.  Perry said that a four-year tuition freeze for incoming freshmen not only gives them certainty about the amount they'll be paying each year but also provides incentive for them to finish their degrees on time.  He said less than 30 percent of students at Texas' four-year institutions graduate in four years and only 58 percent have a degree in six years.