Human trafficking and T-visas statistics

T visas are issued by the US for victims of human trafficking found in the US.   Please note that while "human trafficking" is a term commonly used for the illegal transport of people across national borders, in this case something more is meant:

 Human trafficking, also known as trafficking in persons, is a form of modern-day slavery in which traffickers typically lure individuals with false promises of employment and a better life. Victims of severe forms of human trafficking are provided relief under U.S. immigration law by the Victims of Trafficking in Persons (T) nonimmigrant visa. This status allows victims of human trafficking to remain in the United States to assist in investigations or prosecutions of human trafficking violators.

So, for instance, persons smuggled across the US-Mexico border into the US in return for a payment, without any promise of employment or other benefit, and then left free to seek their own destinies, would not fall into the category of human trafficking for which T visas apply.

T visas made the news when Indian diplomat Ms. Devyani Khobragade was arrested for visa fraud and strip-searched; the visa fraud is alleged in relation to her domestic employee (Mrs Sangeeta Richard) 's A-3 visa; T-visas were used to evacuate members of the Richard family from India.

Some information from the US Department of State is displayed below.  The raw numbers are cut-and-paste from a Department of State spreadsheet, and the (%) column is my computation. Any cut-and-paste errors are mine. 

There is a mystery here just in the numbers, namely  how there can be T-2 visas without T-1 visas. 

The big questions are: what are these human trafficking cases, and is there any US-India cooperation on trying to stem this human trafficking? 

Thanks in advance for any useful information left in the comments.

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US Human Trafficking T-Visas
http://travel.state.gov/visa/temp/types/types_5186.html
Visa	Description
T-1	Primary victim, must be already in the US
T-2	Spouse of victim
T-3	Children of victim
T-4	Parents of victim
T-5	Unmarried siblings of victim under age 18
http://travel.state.gov/visa/statistics/nivstats/nivstats_4582.html
Year (Fiscal Year)	T-visas issued to Indians					Total world-wide T-visas issued					India (%)
	T-1	T-2	T-3	T-4	T-5	T-1	T-2	T-3	T-4	T-5	All T visas
1997	0	0	0	0	0	0	0	0	0	0	0.00
1998	0	0	0	0	0	0	0	0	0	0	0.00
1999	0	0	0	0	0	0	0	0	0	0	0.00
2000	0	0	0	0	0	0	0	0	0	0	0.00
2001	0	0	0	0	0	0	0	0	0	0	0.00
2002	0	0	0	0	0	0	0	0	0	0	0.00
2003	0	0	0	0	0	0	20	38	0	0	0.00
2004	0	23	38	0	0	0	74	145	0	0	27.85
2005	0	10	12	1	0	0	35	65	7	5	20.54
2006	0	3	8	1	0	0	11	43	5	1	20.00
2007	0	2	6	0	0	0	20	70	5	3	8.16
2008	0	2	3	0	0	0	34	132	5	8	2.79
2009	0	0	0	0	0	0	8	81	3	3	0.00
2010	0	13	14	1	0	0	64	167	7	8	11.38
2011	0	82	112	0	0	0	127	258	10	14	47.43
2012	0	49	79	0	0	0	151	342	7	17	24.76