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Mean ± SEM proportion of sleep stages S1, S2, slow wave sleep (SWS) and rapid eye movement (REM) sleep relative to the total time spent asleep.
| Mean | SEM | |
|---|---|---|
| S1 (%) | 22.8 | 4.6 |
| S2 (%) | 44.0 | 3.3 |
| SWS (%) | 16.4 | 2.6 |
| REM (%) | 16.8 | 2.2 |
| Total sleep time (min) | 427.6 | 29.0 |
