Complex sentence: Subframes 4 and 5 contain components of the almanac but each frame contains only 1/25th of the complete almanac; a receiver must process 25 whole frames worth of data to retrieve the entire 15,000 bit almanac message.
Split into simpler sentences: Subframes 4 and 5 contain components of the almanac. Each frame contains only 1/25th of the total almanac; a receiver must process 25 whole frames worth of data to retrieve the entire 15,000 bit almanac message.