The sum of numbers in a line from a file

[kxjakkk]

Let's say I have a sample file like this:

Name        1           2     3    4     5      6     7    8
------------------------------------------------------------------------
name1    099-66-7871   A-F    Y    100    67    81    59    98
name2    999-88-7766   A-F    N    99   100    96    91    90
name3    000-00-0110    AUD        5    100    28    19    76
name4    398-72-3333    P/F    Y    76    84    49    69    78
name5    909-37-3689    A-F    Y    97    94    100    61    79

For name1, I want to add together columns 4, 5, 6, and get an average from that, then do the same for the last two columns. I want to do this for every name. 

All I've got is
sum([int(s.strip()) for s in open('file').readlines()])