1) After looking at some of IRCC data I have found that Rejection rate for overall Permanent Resident was 11% and 9% in 2015 and 2016 respectively. While application through FSW-EE rejection rate was 8% and 10% in 2015 and 2016 respectively. However, for paper-based applications, the rejection rate was 36% and 40% in 2015 and 2016 respectively.
This difference was maybe due to system rejecting many applicants for ineligibility at a very early stage, and this may also be the reason for the significant increase in applications dealt through new EE.
2) Also, for PR card, new applicants rejection rate is 0% while for renewal rejection rate is 2-3 %.
3) In addition to this, total applications received for the first quarter of 2017 was lower than both the 2015 and 2016 figures. This may also be the reason for the high number of ITA's.
4) For further analysis, there is a lot more data available that presents break-up of each NOC and provides insight to which provinces are accepting the most people from the particular NOC.
I hope this will help.
http://open.canada.ca/data/en/dataset/0186868b-a04d-4a0e-962e-bdfbac51bfb3
http://open.canada.ca/data/en/dataset/6bbf2f43-b9d5-49a0-aa8f-71e433340505
http://open.canada.ca/data/en/dataset/1b026aab-edb3-4d5d-8231-270a09ed4e82
http://open.canada.ca/data/en/dataset/53105221-7652-47b1-96e2-1f85715a067c
http://open.canada.ca/data/en/dataset/593e9165-c6ce-4f9b-b519-03d315f92cd4
There are a lot more links and data available but it is very difficult to arrange them, so it needs the effort to find the right file and important data within it. I have just made an attempt to highlight key figures that may not reflect the overall data. I hope others will be able to get better out of it.