A box and whisker plot is a graphical method of displaying variation in a set of data. In most cases a histogram provides a sufficient display; however, a box and whisker plot can provide additional detail while allowing multiple sets of data to be displayed in the same graph. Some types are called box and whisker plots with outliers.
Can you compost Leylandii branches and hedge clippings - Yes. We were quite surprised to learn some experienced composters advise not to add Leyandii cuttings as they are apparently too acidic. Composting bacteria can remain active in all but the most acidic conditions.
Composting is usually a layering of green high-nitrogen materials with brown high-carbon materials. Leaves tend to take longer to break down in a low nitrogen environment and work best when shredded so their breakdown is started mechanically. Also, their breakdown is best facilitated by fungal content to the heap.