1step,rule,n_before,n_after,n_removed,rationale21,"keep one row per (iso3, year)",439,416,23,"Exact-duplicate country-years from merging two extractions (same values, different name label)."32,drop rows with empty life_expectancy,416,415,1,No recorded value; imputation/interpolation is prohibited.43,keep years 2000-2022,415,415,0,Study window.54,keep countries with a recorded value in every year 2000-2022,415,345,70,"Excluded incomplete countries: BGD, CHE, ETH, IND, NGA."6