So apparently, it must be less than 20 g of RDX, and/or a weaker explosive: if the fatal distance was within 0.64 meters, there would be significantly more reported deaths.

Or: lower-abdominal proximity has lower lethality.

That charge, held to the ear, would have had a considerably stronger effect.

Distance in meters?

NB: add two spaces before text for "code" formatting, or two linebreaks between lines.

  Injury/Fatality to Personnel Range (m)
  Fatal Distance 0.64
  Lung Damage 1.02
  Eardrum Rupture 2.63

(I'd found your comment in an Algolia search result which shows your original linebreak as entered.)