Flatten Array to Object using Newtonsoft.Json

EstimatedJurJson.cs

public class EstimatedJurJson
{
    public int RegYear { get; set; }
    public int Distance { get; set; }
}

EstimatedJurModelSerializer.cs

public class EstimatedJurModelSerializer : JsonConverter
{

    public override bool CanConvert(Type objectType)
    {
        return true;
    }

    public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
    {
        var jsonObject = JObject.Load(reader);
        var properties = jsonObject.Properties().ToList();
        return new EstimatedJurJsonModel
        {
            RegYear = StringExtensions.ToInt((string) properties[0].Name, 0),
            Distance = ((string)properties[0].Value).ToInt(0)
        };
    }

    public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
    {
        var obj = value as IEnumerable<EstimatedJurJsonModel>;
        writer.WriteStartObject();

        obj?.ToList().ForEach(s =>
        {
            writer.WritePropertyName(s.RegYear.ToString());
            serializer.Serialize(writer, s.Distance);
        });


        writer.WriteEndObject();
    }
}

StateJson.cs

public class StateJson
{    
    public string CountryCode { get; set; }

    [JsonConverter(typeof(EstimatedJurModelSerializer))]
    public IEnumerable<EstimatedJurJsonModel> EstimatedDistances { get; set; } new List<EstimatedJurJsonModel>();
    public bool Jurisdiction { get; set; }
    public bool DefaultJurisdiction { get; set; }
    public string UnitOfMeasure { get; set; }
}