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

parameters
offset a	slope b
-7.84798e-05	0.00447104

Covariance matrix
3.50857e-11	-1.35644e-09
-1.35644e-09	5.57369e-08

used data points for fitting
energy [keV]	efficiency	efficiency error	nuclide
53.18	9.58098e-05	6.88063e-06	Ba133
81	2.38e-05	1.51607e-06	Ba133
26.35	0.000797146	6.87192e-05	Am241
33.19	0.00040689	4.24366e-05	Am241
59.53	7.37094e-05	6.31901e-06	Am241
