我有6年每月的数据存储在文本文件中，排列如下，每一列表示1年12个月的数据：

330.45 330.97 331.64 332.87 333.61 333.55
331.90 330.05 328.58 328.31 329.41 330.63
331.63 332.46 333.36 334.45 334.82 334.32
333.05 330.87 329.24 328.87 330.18 331.50
332.81 333.23 334.55 335.82 336.44 335.99
334.65 332.41 331.32 330.73 332.05 333.53
334.66 335.07 336.33 337.39 337.65 337.57
336.25 334.39 332.44 332.25 333.59 334.76
335.89 336.44 337.63 338.54 339.06 338.95
337.41 335.71 333.68 333.69 335.05 336.53
337.81 338.16 339.88 340.57 341.19 340.87
339.25 337.19 335.49 336.63 337.74 338.36
我该怎么样读取这些数据呢，SAS中有infile这样的语句，但是它是怎么读的呢，按行还是按列或者可以指定，我有程序如下，用print 语句打出看却没有读到数据，不知道为什么？

libname chap2'e:\work\ex2';
data chap2.ex2(label="Mauna Loa");
infile "e:\ex2.txt" firstobs=1 obs=72  ;
input co2;
time=intnx('month','01jan1975'd,_n_-1);
format time monyy.;
run;
proc print data=chap2.ex2;
run;

结果：

                                                        SAS ϵͳ                     14:12 Wednesday, March 31, 2004   1

                                                  Obs    co2    time

                                                    1     .       JAN75
                                                    2     .        FEB75
                                                    3     .       MAR75
                                                    4     .       APR75
                                                    5     .       MAY75
                                                    6     .       JUN75
                                                    7     .       JUL75
                                                    8     .       AUG75
                                                    9     .       SEP75
                                                   10     .       OCT75
                                                   11     .       NOV75
                                                   12     .       DEC75

请各位指教，多谢了！