Mortality Assumptions

The library supports three standard actuarial assumptions for fractional age calculations:

UDD (Uniform Distribution of Deaths)

Linear interpolation between integer ages:

ₜpₓ = 1 - t · qₓ

CFM (Constant Force of Mortality)

Exponential survival model:

ₜpₓ = (1 - qₓ)ᵗ

HPB (Hyperbolic/Balmer)

Hyperbolic interpolation:

ₜpₓ = (1 - qₓ) / (1 - (1-t) · qₓ)