sysuse uslifeexp, clear
mkspline2 sp_year = year, cubic nknots(3)
qui reg le sp_year* if year != 1918
adjustrcspline,                                            ///
    addplot(scatter le year if year != 1918, msymbol(Oh)|| ///
            scatter le year if year == 1918, msymbol(X))   ///
    name(pred, replace)                                    ///
    title("expected life expectancy in the US")

mfxrcspline,                                               ///
    name(mfx, replace)                                     ///
    ylab(0(.1).5)                                          ///
    title("trend in life expectancy in the US")

graph combine pred mfx,                                    ///
    ysize(3)                                               ///
    note("excluding 1918 due to the Spanish flu pandemic")