Poly said:
Perhaps you could tell us what "field" you got your information from.
Bullinger (Lightfoot), Grabacka, Gunther, Tertullian, Origen, the P46 manuscipts, the Athanasius documents, Amphilocius, Theodore, the Synod of Laodicea, Marcion, Ephraem, and the Mt. Sinai manuscripts.
Bullinger's list was the one nearest to me when I read Kmo's request.
I'll give you Gunther's complete breakdown, though his will surely raise some eyebrows (and rightly so.)
1. Thessalonians ~ 51 CE
2. Galatians ~ 54 CE
3. the "1 Corinthian 5:9" letter ~ 55 CE
4. 1 Corinthians ~ October of 55 CE
5. 2 Corinthians 10 - 13 ~ May of 56 CE
6. Philippians 3:1b-19 ~ late summer of 56
7. 2 Corinthians 1 -9 ~ late summer 56
8. Romans 1-15 ~ 57
9. Romans 16 ~ late winter of 57
10. Colossians, Ephesians, Philemon, Titus ~ April - May of 59
11. Philippians 1-3,1a,20-4 ~ May of 59
12. 2 Timothy 4:9ff ~ August of 59
13. 1 Timothy 1:12-16 ~ 60-61
14. 2 Timothy 1:1-10, 12, 15-2:1, 3, 8-10, 4:5 ~ 60-61
15. Hebrews ~ 62-63
Let it be known that I don't agree with all that Gunther has put forward, but it'll give you and anyone else interested a look at what some others have thought.