Mean comparison

[Youssef1]

Dear,

I am trying to compare the mean of return when USR=0 versus 1.

Any help in the appropriate method is much appreciated

Cheers


Date RETURN USR
02/09/1997 -0.0006 0
03/09/1997 0.0173 0
04/09/1997 -0.0051 0
05/09/1997 0.0069 0
08/09/1997 -0.0006 0
09/09/1997 0.0027 0
10/09/1997 -0.0057 0
11/09/1997 0.0024 0
12/09/1997 0.0050 0
15/09/1997 -0.0010 1
16/09/1997 0.0048 1
17/09/1997 -0.0100 1
18/09/1997 0.0049 1
19/09/1997 -0.0132 1
22/09/1997 -0.0031 1
23/09/1997 0.0004 1
24/09/1997 -0.0233 1
25/09/1997 -0.0036 1
26/09/1997 0.0089 1
29/09/1997 0.0014 1
30/09/1997 0.0015 1
01/10/1997 -0.0122 1
02/10/1997 -0.0177 1
03/10/1997 0.0230 1
06/10/1997 0.0042 1
07/10/1997 -0.0068 1
08/10/1997 -0.0013 1

[startz]

What have you done so far?