Keep the unknown interval in view
Suppose the report gives 2% LE from 0–20 cm, no LE from 20–55 cm, and 7.5% LE from 55–100 cm. Only 20 + 45 = 65 cm have values. The other 35 cm remain unrated.
A blank LE field is different from a reported value of zero. Zero is included in rated thickness and in the arithmetic. Missing LE is not treated as zero, copied from a neighboring layer or extrapolated through a gap.
Show the highest band separately
The example's highest entered LE is 7.5%, in the High screening band used by GroundShiftCheck. We retain that result separately. It does not say where a foundation sits within a map unit or whether a structure has a defect.