Good morning monks. I have data in the form of 

ID   Date (MMYY)   Value
1   0109           4
1   0209           5
1   0309           8
.   .              .
.   .              .
2   0109           6
2   0209           6
.   .              .
.   .              .
.   .              .

[download]
And so forth. I want to take an average of every value that equals a specific date, so what is the average value for each ID that matches the date 0109 for example I don't need an entire program written for me, but an explanation of how to best proceed in doing this. Also there is a lot of data, so its not feasible to use if ($date = 0109) { ... } Thanks monks!

In reply to Calculating the average on a timeslice of data by perlbrother

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