We just got the results from my 5-year-old's Woodcock Johnson III achievement test. There is no score for total achievement. Does anyone know how to calculate it?

Here are his scores for the individual batteries (score, followed by percentile):

Letter-Word Identification 156 >99.9
Reading Fluency 146 99.9
Calculation 139 99.6
Math Fluency 128 97
Spelling 137 99
Writing Fluency 112 78
Passage Comprehension 141 99.7
Applied Problems 148 >99.9
Writing Samples 134 99

Thanks!