Table 3.

State Development over PMA Groups (Mean (SD)) (n = 285 video recordings)

		Postmenstrual Age (weeks)
	Total	31-32	33-34	35-36	37-38	39-40
Observations (n)	285	6	125	116	35	3
Range of states
Quiet sleep (%)	0.56 (2.96)	0.00	0.35 (1.90)	0.97 (4.16)	0.14 (0.74)	0.00
Active sleep (%)	85.02 (15.67)	88.75 (9.22)	84.93 (14.75)	84.75 (17.19)	84.52 (15.16)	97.85 (0.66)
Drowsy (%)	11.50 (12.96)	9.84 (7.24)	12.17 (12.27)	10.8 (14.39)	11.94 (11.56)	1.82 (0.85)
Awake (%)	2.91 (5.82)	1.41 (3.18)	2.55 (4.99)	3.30 (6.72)	3.40 (5.97)	0.33 (0.57)
Maturity of states
Diffuse (%)	13.98 (10.73)	17.01 (13.09)	14.53 (11.84)	13.35 (9.94)	14.35 (8.84)	4.87 (5.55)
Defined (%)	85.66 (11.12)	82.99 (13.09)	85.30 (11.82)	85.98 (10.91)	85.54 (9.12)	95.13 (5.55)