Complex sentence: Of note, 2006 is the 25th year running that Oaxaca's teachers have staged a strike; usually it lasts a week or two, they receive a small raise, and then get back to work.
Split into simpler sentences: Of note, 2006 is the 25th year running that Oaxaca's teachers have staged a strike. Usually it lasts a week or two: they receive a small raise, and then get back to work.