Table 2. Demographic parameters of patients included in to the study.

Over the observation period of 30 years we observed an increased age of study populations. The meant Injury Severity Score (ISS) has shown a wide range between 9 points and up to 62.3 points.

References	Age (Years)	Gender (% of Male)	ISS (Points)
(Baker et al., 1980)[7]	65%<51	75.3	mean 43
(Pories et al., 1989)[19]	median 28	74	mean 9
(Shackford et al., 1989)[20]	mean 34.5	ND	mean 49.5
(Sahdev et al., 1994)[9]	mean 35	88	mean 37.8
(Sauaia et al., 1995)[18]	mean 36.8	79	mean 35.7
(Meislin et al., 1997)[17]	mean42.9–49.3	79.6–67.9	Mean 39–25.6
(Hodgson et al., 2000)[21]	median 39	72	mean 30–43
(Marson et al., 2001)[22]	mean 33.9–35.3	81.3–82.8	ND
(Chiara et al., 2002)[14]	mean 44–55	73	mean 27.5–62.3
(Stewart et al., 2003)[23]	mean 42.5	ND	mean 41.2
(Tien et al., 2007)[24]	mean 48.7	71.2	mean 38.8
(Søreide et al., 2007)[11]	mean 45.8	75	median 38
(Pang et al., 2008)[25]	mean 36.5	74	median 25
(Evans et al.,2010)[15]	mean 55	55	mean 36
(Kleber et al. 2012) [26]	mean 58	64.1	ND

ND = no data