雅思写作 | 饼图中占比多少的相关表达

constitute 

Globally, 65% of degradation is caused by too much animal grazing  and tree clearance, constituting 35% and 30% respectively.

account for 

Other reasons account for only 7% collectively.

（collectively adv. 共同地，全体地）

XXX% of ... is due to 

A further 28% of global degradation is due to over-cultivation of crops.