Deserializing Json array with variable names first using C# Json.NET

I'm getting an irregular JSON array from the Census Bureau's public api. The variable names are all in the first element, and I'm having trouble deserializing it.

http://api.census.gov/data/2014/pep/agesex?get=AGE,POP,SEX&for=us:*&DATE=7

gives me JSON like this:

[["AGE","POP","SEX","DATE","us"],
["0","3948350","0","7","1"],
["1","3962123","0","7","1"],
["2","3957772","0","7","1"],
["3","4005190","0","7","1"],
["4","4003448","0","7","1"],
["5","4004858","0","7","1"],
["6","4134352","0","7","1"],
["7","4154000","0","7","1"]]

I can successfully deserialize this using:

var test1 = JsonConvert.DeserializeObject<String[][]>(jsonStr);

However, I'm trying to deserialize it to a class like this:

public class TestClass
{
    public string AGE { get; set; }
    public string POP { get; set; }
    public string SEX { get; set; }
    public string DATE { get; set; }
    public string us { get; set; }
}

I'm trying to do this:

var test2 = JsonConvert.DeserializeObject<TestClass[]>(jsonStr);

But I'm getting the following exception:

An exception of type 'Newtonsoft.Json.JsonSerializationException' occurred in Newtonsoft.Json.dll but was not handled in user code

Additional information: Cannot create and populate list type TestClass. Path '[0]', line 1, position 2.