From when are the years counted?
Rashi: From Nebuchadnetzar's reign. That year, Egypt was given to him, like it says in Seder Olam (26 1 ). Many Nevu'os in this Sefer are out of order! Radak ? he plundered Egypt, and exiled Yirmeyah and Baruch to Bavel. Malbim ? here the verse does not count from Galus Yehoyachin, in order that we will know when Egypt's 40 years of desolation (14) begin. We infer that the 40 years finished when Evil Merudach died.
Radak: It says there also that in Nebuchadnetzar's 23rd year, Nevuzaradan (his chief killer) exiled 745 Yisraelim, like it says in Yirmeyah (52:30). Then he was given Tzor, and he inundated all the Jews in Amon, Mo'av and around Eretz Yisrael. (This is unlike the Bavli, which implies that Nevuzaradan converted at the time of the Churban (Gitin 57b), which was in Nevuchadnetzar's 19th year. ? PF)