ðə pɚsˈɛntɪdʒ fɹˈiːkwənsi ʌv kˈɔːɹɾɛks ɪz ɐn ɪmpˈoːɹtənt stɐtˈɪstɪk tə hˈɛlp aɪdˈɛntᵻfˌaɪ lˈɪθɪk pɹədˈʌkʃən ˈɛɹiəz.
The percentage frequency of cortex is an important statistic to help identify lithic production areas.