My friend, issuance of 43000 till now, that means nothing, because there are a lot of people who can not submit all the documents or some documents. And also, there are some ITA invitees who rejected the invitation because of a small mistake or something else. Another point is the medical control, unfortunately some applicants can not pass this med test. In conclusion, CIC tries to fill that gap by inviting more than 73700. I may say that number could reach up to 90000 by the end of this year. Hope you understood my opinion. May everyone get an ITA at this year (2017)!