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

parameters
offset a	slope b
-1.80686e-05	0.00104251

Covariance matrix
1.22161e-12	-4.8792e-11
-4.8792e-11	2.04262e-09

used data points for fitting
energy [keV]	efficiency	efficiency error	nuclide
53.15	2.3004e-05	1.2699e-06	Ba133
80.98	5.68556e-06	2.45912e-07	Ba133
26.34	0.000181916	1.31477e-05	Am241
33.19	9.32855e-05	8.65243e-06	Am241
59.54	1.73782e-05	1.24589e-06	Am241
