In general, the bigger the drive, the higher the failure rate. However failure rate is measured by drives returned between 6 and 12 months before the end of the reporting period.... so the this2016 report, I expect it was for drivers purchased that were 6 - 12 months old on March 31 2016
http://www.hardware.fr/articles/947-6/disques-durs.html
The failure rate for the last 2 periods was a combined :
HGST: 0.70 %
Seagate: 0.64 %
WD: 0.95 %
Toshiba: 1.05 %
OTOH... look at the 5 worst drives and most of them are all large 3-4 TB drives. Does that mean 6 TB drives are fine ? No. The absence of a drive in the list doesn't mean it had a low failure rate ... it just means they did not sell enough to reach a statistical threshold...