Two alternate "Spline2" to HadCRUt4 have been added:
1. a Poly4, not yet to my Smath satisfaction, but works.
2. a "linfitCheby5" in separate work sheet.
For this application, they both almost equate "Spline2"

Jean

Inst_HadCRU.sm (291 KiB) downloaded 74 time(s).

Inst_HadCRU [linfitCheby].sm (128 KiB) downloaded 72 time(s).