Fig. 7. Calculation of calcium to phosphorus (Ca/P), calcium to carbon (Ca/C) ratio and the sum of calcium and phosphorus (Ca + P) for the determination of bone decomposition/aging. (A) Calcium to phosphorus (Ca/P) ratio: Ca/P increases with PMI. (B) Calcium to carbon ratio increases with PMI. (C) The C + P was used to determine the mineralogical content, which increases with PMI.