| - | >1 SD below mean normal value |
| + | Within ± 1 SD of mean normal value |
| ++ | >1-2 SD above mean normal value |
| +++ | >2 SD above mean normal value |
| - | >1 SD below mean normal value |
| + | Within ± 1 SD of mean normal value |
| ++ | >1-2 SD above mean normal value |
| +++ | >2 SD above mean normal value |