This spreadsheet is created by Dr. John G. Cramer based on calculations in following paper: Levine ME, Lu AT, Quach A, Chen BH, Assimes TL, Bandinelli S, et al. An epigenetic biomarker of aging for lifespan and healthspan. Aging (Albany NY). 2018;10(4):573–91.

There is no evidence that the spreadsheet is under copyright. I have emailed Dr. Cramer alread and will update his response here.