Interesting you brought this up. I just found this
"What is a grade equivalent, and what does it mean?
A grade equivalent (GE) is a score reported on norm-referenced tests that allows educators and parents to compare students based on the performance of other students relative to the school year. Based on a 9-month school year (typically September through May), the score represents a period during the school year, displayed as a number to show a grade and a month. The score is an estimate of the performance that an average student at a grade level is assumed to demonstrate on the test at a particular time in the school year. For example, a score of 5.8 represents a performance level typical of fifth-grade students in the eighth month (April) of the school year. It is important to note that grade equivalent scores outside the current grade are common and should be interpreted with caution. For example, a fifth-grade student could receive a grade equivalent score of 7.4. This does not mean the student can perform seventh-grade work � the student would not have been exposed to seventh-grade content, nor would a fifth-grade test contain seventh-grade content. It suggests that a typical seventh grader in the fourth month would have received the same score if seventh graders had taken the fifth-grade test."
