Derivation
variable: resistance_ohms_bs (table[s]: NUTdata_KAR, NUTdata_LLW)
variable: resistance_ohms_bs_2 (table[s]: NUTdata_KAR, NUTdata_LLW)
variable: res_final (table[s]: gap_combined)
<NUT data:>
egen resval=rowmean(resistance_ohms_bs resistance_ohms_bs_2)