Table 2. Whole-genome sequencing quality metrics according to sample storage time.

Variable	All n = 85	0–10 y n = 11	11–15 y n = 12	16–20 y n = 28	21–30 y n = 34	Min	Max
Coverage (x)	11.3 (9.0–15.9)	12.2 (10.7–18.2)	10.9 (9.6–14.6)	10.4 (9.2–17.7)	11.2 (8.4–15.4)	3.8	55.5
% Covered 20x	15.8 (12.4–29.4)	16.0 (11.2–29.7)	13.6 (11.3–22.0)	14.9 (13.9–31.2)	17.3 (11.1–29.4)	0.8	97.2
% Covered 10x	40.9 (25.3–58.4)	54.7 (43.4–61.5)	42.0 (28.4–60.9)	38.2 (26.3–63.2)	36.0 (20.3–53.2)	9.3	97.9
% Covered 0x	2.9 (1.9–4.0)	2.2 (1.9–3.0)	2.7 (2.0–3.7)	2.9 (1.9–3.5)	3.4 (2.2–4.7)	1.1	26.2
% Q20	77.0 (70.8–82.1)	80.8 (75.7–84.0)	79.4 (73.4–83.1)	76.8 (73.0–84.0)	74.2 (67.7–79.8)	40.5	93.9
Library size	1.7 (1.4–2.7)	2.8 (1.7–3.2)	1.7 (1.4–2.0)	1.7 (1.5–3.0)	1.6 (1.3–2.4)	0.87	8.61
Ti/Tv Ratio	2.09 (0.05)	2.09 (0.03)	2.09 (0.03)	2.08 (0.04)	2.09 (0.07)	1.94	2.28

Quantitative data are expressed as medians and interquartile ranges or means and standard deviations. Coverage is expressed as depth of coverage (x). Proportions of observations covered at 20x, 10x and 0x are expressed as percentages (%). Proportions of observations with a Phred quality score of Q20 are expressed as percentages (%). Library sizes are presented in gigabases (billion base pairs). TiTv ratios are expressed as means and standard deviations.