```ruby
class AddWellConnectedAndImportanceToCountryStatistic < ActiveRecord::Migration
  def change
    add_column :country_statistics, :well_connected, :float
    add_column :country_statistics, :importance, :float
  end
end
```

Add stats for marine as well
user
```ruby
class AddWellConnectedAndImportanceToCountryStatistic < ActiveRecord::Migration
  def change
    add_column :country_statistics, :percentage_land_well_connected, :float
    add_column :country_statistics, :percentage_marine_well_connected, :float
    add_column :country_statistics, :percentage_land_importance, :float
    add_column :country_statistics, :percentage_marine_importance, :float
  end
end
```
assistant