Graduation rates declined in three of York County's four school districts last year, according to statewide data released today.
Only the Fort Mill school system improved: The 2010 on-time graduation rate nudged up to 91.9 percent from 90 percent the year before. Nation Ford High's graduation rate of 92.6 percent was the county's highest.
Rock Hill, Clover and York high schools' rates declined.
Rock Hill - with a graduation rate of 70.7 percent - fell below the state's rate of 72.6 percent.
York's rate of 79 percent is down from 83.6 percent in 2009. Clover's rate is 73.9 percent, down from 78.5 percent.
Results were similar across South Carolina, where on-time graduation rates for most public high schools dipped.
Fifty-nine percent of high schools reported lower rates, according to the S.C. Department of Education. Rates for 26 schools dropped by at least 10 percentage points.
The graduation rate, calculated by tallying the number of ninth-graders who earn diplomas four years later, is posted annually on report cards issued by the state. The 2010 report cards for elementary and middle schools were published in November.
Changes in the way graduation rates are calculated delayed high school and district report cards, according to the Department of Education.
Education officials partly blame those changes for the widespread decline in graduation rates.
South Carolina now calculates the rates using a method that federal law will soon require all states to adopt. It forces schools to keep meticulous records and track students. Students whom a district loses track of can count against the graduation rate.
"The aim is produce more accurate figures that will account for dropouts and others who don't graduate from high school with a regular diploma," S.C. Deputy Superintendent for Accountability Nancy Busbee said.
For 2010, districts were required to provide more paperwork than in previous years, some of which was difficult to track down, Clover schools Associate Superintendent Sheila Huckabee said.
With more time, Huckabee believes the district could have provided a "more accurate representation of who came into ninth grade four years ago."
For example, she said, early in the calculation process the state counted eighth-graders as ninth-graders because they were enrolled in a high school-level course.
Clover had to provide paperwork proving those students weren't actually in ninth grade four years ago.
"I'm not sure if our graduation rate (actually) dropped or stayed the same based on the calculation," York schools Superintendent Vernon Prosser said.
In time though, Prosser said he believes the new system will lead to more accurate graduation rates. And for the first time, states will be able to compare themselves to each other.
"It puts us all on the same page," Prosser said.
Rock Hill schools Superintendent Lynn Moody said she understands why states report graduation rates, but thinks it's an outdated approach.
"I am much more interested in how many students graduate, not when," she said. "Time shouldn't be a factor. Kids learn in different periods of time. We've got to get out of the box of thinking high school is four years. What's magical about four years?
"We have to think harder about mastering concepts. For some students, that takes longer. For others, it's quicker."
S.C. public schools track high school completion in two ways: the graduation rate and dropout rate.
The graduation rate is calculated by counting the number of ninth-graders who earn diplomas four years later.
The dropout rate tracks how many students leave each year.