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

parameters
offset a	slope b
-0.000420594	0.0233281

Covariance matrix
2.34904e-09	-8.71495e-08
-8.71495e-08	3.48804e-06

used data points for fitting
energy [keV]	efficiency	efficiency error	nuclide
53.15	0.000516266	6.19676e-05	Ba133
80.98	0.000120477	1.39353e-05	Ba133
26.33	0.00416047	0.000545256	Am241
33.18	0.00210306	0.000301288	Am241
59.53	0.000380685	4.97742e-05	Am241
