AGE DEPENDENCE OF SKIN PROPERTIES 223 x :5 + ß II oo o x

224 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS Table II Values of the Measured Parameters Calculated According to Table I At Age 20 At age 70 % Change Indentation 0. 043 cm 0.054 cm 26 Elastic recovery 80.5 % 65.5 % 19 Levarometry (slackness) 0. 037 cm 0.068 cm 84 Surface pH 5.25 5.61 7 In order to see whether the distribution is homogeneous, we present the histograms of Figures 1-4. It is clear that, except for the skin pH (Figure 4), the data are unho- mogeneous with respect to age. In the pH histogram there is no obvious distribution difference between the 20-39 age group and the 40-70 age group, with the exception Distribution of Indentation ø•Age 20-39y: 95 91 95 79 83 74 66 64 50 40 • 75 •50 25 0 ..J! N=446 20 22 24 26 28 30 32 34 •_19 21 23 25 27 29 31 33 35 __,36 Units 60 Units: 0.1 cm Indentation Figure 1. Distribution of indentation. The "young age" (20-39 years) cases are shown by a dotted line. The unbroken line shows the total number of cases.