Looks like the problem is in the way [`ruby-cldr`](https://github.com/svenfuchs/ruby-cldr) dump data. Specifically, in the way they override [this method](https://github.com/svenfuchs/ruby-cldr/blob/master/lib/cldr/export/yaml.rb#L31-L37) of `Ya2YAML` class. With this method override you always get numeric strings without quotes (that are later parsed by the standard Ruby YAML parser as integers in TwitterCLDR):
```ruby
1.9.3p362 :001 > Cldr::Export::Yaml.new.yaml("en"=>{"territories"=>{"001"=>"World", "002"=>"Africa", "003"=>"North America"}})
 => "en: \n  territories: \n    001: World\n    002: Africa\n    003: \"North America\""
```

Without this override (if you comment it and use the original implementation from `ya2yaml` lib) you get quotes around keys:
```ruby
1.9.3p362 :001 > Cldr::Export::Yaml.new.yaml("en"=>{"territories"=>{"001"=>"World", "002"=>"Africa", "003"=>"North America"}})
 => "en: \n  territories: \n    ? \"001\"\n    : World\n    ? \"002\"\n    : Africa\n    ? \"003\"\n    : \"North America\""
```
It looks better, but for some reason this YAML string can't be parsed by standard Ruby YAML parser. Probably the fix in `ruby-cldr` should be a bit more accurate than just commenting `is_one_plain_line?` method :) If you're interested, you can dig deeper and try to fix the way `ruby-cldr` dumps data. I think it'd be great to get it fixed rather than ignore these type of codes.

FYI, standard Ruby YAML engine tries to omit quotes around strings when possible, but it leaves them if the string represents a valid octal number (with '0' prefix):
```ruby
1.9.3p362 :010 > YAML.dump(['001', '008', 'foo'])
 => "---\n- '001'\n- 008\n- foo\n"
```
Looks like that's how it should be according to the YAML spec and I think that is what we need to get in the YAML files generated by `ruby-cldr` to solve this problem.