Read a company's annual report....you can find them here.... https://www.sec.gov/cgi-bin/browse-edgar?action=getcompany&CIK=0000029504&type=&dateb=&owner=include&count=40 or here is an easier link... https://www.sec.gov/cgi-bin/browse-edgar?action=getcompany&CIK=0000029504&type=10-k&dateb=&owner=include&count=40