Sun movement throught the year in Johor

Since the Islamic prayer timings are based on the position of the sun I was curious about how the Zohor prayer time changes throughout the year. Zohor Prayers start when the sun is directly overhead.

Countries outside the tropics experience a single transition from long days to short ones because the sun is closest only once a year. In the tropics however the sun makes two such transitions. However the highs and lows are uneven depending on where in the tropics you are. The steepest downward slopes seem to be related to the Vernal and Autumnal equinoxes while the lows are related to the summer and winter solstices (but not exactly correlated).