First and Second Imprisonments at Rome. On the way, Paul and those with him experienced shipwreck on the island of Malta. After wintering there, they finally arrived at Rome. (MAP, Vol. 2, p. 750) Paul was permitted to stay in his own hired house, though under soldier guard. Shortly after his arrival, Paul arranged a meeting with the principal men of the Jews. But only some believed. The apostle continued to preach to all those who came to him for two years, from about 59 to 61 C.E. (Ac 27:2–28:31) During this time he also wrote his letters to the Ephesians (4:1; 6:20), Philippians (1:7, 12-14), Colossians (4:18), to Philemon (vs 9), and evidently also to the Hebrews. (PICTURE, Vol. 2, p. 750) It appears that Caesar Nero pronounced Paul innocent and released him. Evidently Paul renewed his missionary activity, in association with Timothy and Titus. After having left Timothy at Ephesus and Titus on Crete, Paul, probably from Macedonia, wrote letters to them relative to their duties. (1Ti 1:3; Tit 1:5) Whether the apostle extended his activity to Spain before his final imprisonment at Rome is not known. (Ro 15:24) During that imprisonment (c. 65 C.E.) Paul wrote his second letter to Timothy, wherein he implied that his death was imminent. (2Ti 4:6-8) Likely Paul suffered martyrdom at the hands of Nero shortly thereafter.

Seahorse has given some useful information on the subject, quoting an authoritative Bible encyclopedia. This truly as much as we know on the subject. Since we don't know when Paul was born, we can't know his age at death. It seems that he was slightly younger than the 12 apostles and so likely also born later than Jesus. This is not fact, but an educated deduction. The answer really has nothing to do with the NWT. The facts come out the same regardless of Bible version. If you use the NWT and other mainline Bibles much, you will notice that there are very few real differences. Regardless of translation, you can learn the truth. The NWT is useful because it has discarded human tradition and religious dogma in rendering the original languages; this gives it a freshness and vigor that most versions lack. Hope this answers your question.