Table 1 Coefficient estimates

GM

a = − 0.0022, b = 495.2651

FGM

r = 0.6155, a = 0.0644, b = 378.6288

GBPM

t = 6, a = − 0.0597, b = 409.7168, c = − 135.2210

OGBPM

t = 6, a = − 0.0597, b = 409.7168, ε = 0.0922, c = 227.7881

NOGBPM

t = 7, a = − 0.0581, b = 410.4514, ε = 0.0830, c = 195.4888, α = 0.5366, β = 0.7270

NGBPM

t = 4, α = 0, β = 1, a = 0.0061, b = 463.0535, c = 54.0779,

AGBPM

t = 8, a = − 0.0339, b = 440.5392, ε = 0.0259, α = 0.9646, β = 1