State code

https://www.google.co.in/url?sa=t&source=web&rct=j&url=https://www.ddvat.gov.in/docs/List%2520of%2520State%2520Code.pdf&ved=0ahUKEwiq3ZzY2-bSAhVGtJQKHV8kC0EQFggkMAE&usg=AFQjCNGSu4Y7RaV9H49yASzaXFPzizJQLw

Sr. No. State Name TIN number – State Code
1Andaman and Nicobar Islands 35 AN
2 Andhra Pradesh 28 AP
3 Andhra Pradesh (New) 37 AD
4 Arunachal Pradesh 12 AR
5 Assam 18 AS
6 Bihar 10 BH
7 Chandigarh 04 CH
8 Chattisgarh 22 CT
9 Dadra and Nagar Haveli 26 DN
10 Daman and Diu 25 DD
11 Delhi 07 DL
12 Goa 30 GA
13 Gujarat 24 GJ
14 Haryana 06 HR
15 Himachal Pradesh 02 HP
16 Jammu and Kashmir 01 JK
17 Jharkhand 20 JH
18 Karnataka 29 KA
19 Kerala 32 KL
20 Lakshadweep Islands 31 LD
21 Madhya Pradesh 23 MP
22 Maharashtra 27 MH
23 Manipur 14 MN
24 Meghalaya 17 ME
25 Mizoram 15 MI
26 Nagaland 13 NL
27 Odisha 21 OR
28 Pondicherry 34 PY
29 Punjab 03 PB
30 Rajasthan 08 RJ
31 Sikkim 11 SK
32 Tamil Nadu 33 TN
33 Telangana 36 TS
34 Tripura 16 TR
35 Uttar Pradesh 09 UP
36 Uttarakhand 05 UT
37 West Bengal 19 WB

Thanks lot

What is the difference between state codes of 28(AP) and 37(AD)?