Join two tables from Wikipedia to render list of counties sorted by kilometres of paved roads per capita.

PavedRoadsPerCapita.fsx

#!/usr/bin/dotnet fsi

#r "nuget: FSharp.Data, 4.2.2"
open FSharp.Data
open System

type RoadsHtml = HtmlProvider<"https://en.wikipedia.org/wiki/List_of_countries_by_road_network_size">
let roadsHtml = RoadsHtml.GetSample()

let roads = 
    [ for row in roadsHtml.Tables.Table1.Rows do
        let cname, pavedRoads = row.Column1.Replace("(more)","").Trim(), row.Column4
        if not (Double.IsNaN pavedRoads) then
            yield cname, pavedRoads
    ]
    |> Map.ofList

type CountriesHtml = HtmlProvider<"https://en.wikipedia.org/wiki/List_of_countries_by_population_(United_Nations)">
let countriesHtml = CountriesHtml.GetSample()

printfn "paved-roads/cap, country, population, paved-roads, region, subregion"

[ for row in countriesHtml.Tables.Contents.Rows ->
    let cname, population = row.``Country/Area``, row.``Population (1 July 2019)``
    let region, subregion = row.``UN continental region[4]``, row.``UN statistical subregion[4]``
    let cname = cname.Split('[').[0].Split('(').[0].Trim()
    match roads |> Map.tryFind cname with
    | None -> 0.0, cname, population, None, region, subregion
    | Some kilometres -> (float kilometres / float population), cname, population, Some kilometres, region, subregion
    
]
|> List.sortBy (fun (kpc,c,p,k,r,sr) -> -kpc)
|> List.iter (printfn "%A")