int_std_atm.csv
Taken from the ISA wikipedia page.
https://en.wikipedia.org/wiki/International_Standard_Atmosphere

layer - is the layer number 0 being closest to the surface  
level_name - is the layer name  
h - is the geopotential altitude in m  
z - is the geometric altitude in m  
lapse_rate - is the lapse rate in K/km of geopotential altitude  
T - is the base temperature for that layer  
P - is the base pressure for that layer  
rho - is the base density for that layer