How to make mysql case then in laravel query builder

I have this mysql query:

select
  case
    when country like '% usa %' then 'usa'
    when country like '% italy %' then 'italy'
    when country like '% china %' then 'china'
    when country like '% india %' then 'india'
  end as ccountry,
  count(*) as population
from
  (
    select concat(' ', country, ' ') as country
    from Table1
    where city = 'cityName'
  ) T
group by ccountry

i've already try using this query:

$subQuery = Table1::selectRaw("concat(' ', country, ' ') as country")
  ->where('city', 'cityName');

and this is the next query:

$query = DB::table(DB::raw('('.$subQuery->toSql().') as T')) 
  ->select(DB::raw("case
      when country like '% usa %' then 'usa'
      when country like '% italy %' then 'italy'
      when country like '% china %' then 'china'
      when country like '% india %' then 'india'
    end as ccountry"), DB::raw('count(*) as population'))
  ->groupBy('ccountry') 
  ->get();

And this is the error message: SQLSTATE[HY000]: General error: 2031 No data supplied for parameters in prepared statement

select
  case
    when country like '% usa %' then 'usa'
    when country like '% italy %' then 'italy'
    when country like '% china %' then 'china'
    when country like '% india %' then 'india'
  end as ccountry,
  count(*) as population
from
  (
    select concat(' ', country, ' ') as country
    from Table1
    where city = ?
  ) T
group by ccountry

i think, the problem is because the value of where city becomes a question mark (?) please if anyone can help, I'm very grateful.