However, this release focusses on the first 10 years of the projection period, as projections tend to become increasingly uncertain in the longer-term, as trends may change over that timescale.
Dylid nodi bod yr adroddiad hwn yn dangos patrymau dros gyfnod cymharol fyr ers cyflwyno'r asesiadau personol, ac y bydd angen data rhagor o flynyddoedd i lunio barn ar dueddiadau tymor hwy.