what i understood from the spreadsheet is that application lodged in 2017 taking way long than other applications before or after 2017.
few of them took only 4 to 9 months only or 1-year max 14 months.
when the rule changed in 2017 for 187 loads of applications were lodged most of them were bogus and applications refusal rate skyrocketed all these applications in 2017 especially June, July and August deemed high-risk applications and were put aside.