You probably need to make 2 method calls. 1 to get the total results, and then loop the other to get each result. Something like this:
fetchedResults = 0
progress = 0
results = 
Meteor.call 'getTotalResults', (err, totalResults) ->
# e.g. returns 100 results
for i in [1..totalResults]
# now request each result. Mind that this is async.
Meteor.call 'getResult', (err, result) ->
progress = (fetchedResults / totalResults) * 100
Hope this helps.