96 



BELL SYSTEM TECHNICAL JOURNAL 



4000 



4000 



— — — — — — — — — — CMt\JCy(\JC\Jt\Jf\IC\J(\JC\Jfr) 



Fig. 66 — Growth of various classes of physical property of the Bell System. 



o — f\in^«'><oi~-(0<j)o — (\iro^>n(£)h-<oo>o— (\j(0^ inioi^oo 



OOOOOOOOOO— — — —— — — — — — (M(\|(\j(\J(\|(\j(\)(\j(\| 



Fig. 67 — -Bell System revenues in millions of dollars. 



