Monthly returns, NYSE. Jan. 1961-Dec. 1967.
#see also ATT.1, IBM.1
  0.082320
  0.059360
  0.050370
  0.008410
  0.041790
 -0.042420
  0.010950
  0.021040
 -0.029710
  0.021330
  0.046410
 -0.003510
 -0.007930
  0.015540
 -0.005940
 -0.068300
 -0.098000
 -0.084750
  0.063690
  0.027960
 -0.060500
 -0.021920
  0.137300
 -0.009060
  0.078160
 -0.015080
  0.020950
  0.039020
  0.032420
 -0.015830
 -0.009520
  0.050560
 -0.018410
  0.016330
 -0.006820
  0.007520
  0.020080
  0.026990
  0.031400
 -0.003050
  0.011640
  0.015400
  0.027670
 -0.008960
  0.036990
  0.017000
  0.000720
 -0.006910
  0.058710
  0.027840
  0.005280
  0.035920
 -0.007900
 -0.074330
  0.029100
  0.045090
  0.030830
  0.047390
  0.030050
  0.032670
  0.043530
  0.010940
 -0.021870
  0.033740
 -0.072380
 -0.004830
 -0.012660
 -0.093050
 -0.014320
  0.012690
  0.038250
  0.016230
  0.142850
  0.020940
  0.052010
  0.036480
 -0.017880
  0.051640
  0.070920
  0.002800
  0.037770
 -0.035940
  0.006690
  0.055440