Used file for the fit: SDD_normalized-Efficiency_point-source_with-air_all-levels.csv

parameters
offset a	slope b
-1.72983e-05	0.00100608

Covariance matrix
1.14958e-12	-4.56921e-11
-4.56921e-11	1.90718e-09

used data points for fitting
energy [keV]	efficiency	efficiency error	nuclide
53.16	2.23063e-05	1.20829e-06	Ba133
80.99	5.63228e-06	2.4388e-07	Ba133
26.34	0.000175716	1.27027e-05	Am241
33.18	9.20036e-05	8.58357e-06	Am241
59.53	1.66759e-05	1.19576e-06	Am241
