Energy | 6 MV | 6 FFF | 15 MV | 6 MeV | 9 MeV | 12 MeV |
ρ | −0.231 | −0.445 | −0.331 | −0.379 | −0.416 | −0.178 |
n | 29 | 21 | 26 | 24 | 24 | 27 |
p-value | 0.229 | 0.043 | 0.098 | 0.068 | 0.043 | 0.375 |