You did a great job, I corrected only small things. :)

Thank you so much if you will provide some useful corrections and tips! 

The pie chart below provides data on the average age of yYemeni and iItalian inhabitants in 2002. It also shows a future projection for 2050. Ages of pPeople are divided by age into three categories (0-14 years old; 15-59 years old; 60 years old and older). 

Overall, by 2050, the number of people with ages between 15 and 59 years old people is expected to increase in Yemen, whereas in Italy it will fall. At the same time, while the share of feature for people older than 60 is forecasted to increase in Yemen, in Italy it will impressively grow impressively in Italy. 

As we can see from the chart, in Yemen, in 2000, Yemeni people aged 0-14 years accounted for over half of the total population; this rate feature is expected to decrease in 2050, when they will be drop to around 37% of the total population. At the same time, the group of middle-aged people (15-59 years) will increase (rising from approximately 47% in 2000 to around 57% in 2050). It is clear that the number of old people - aged more than 60 years - won't change remarkably. 

On the other hand, the Italian situation is fairly different: while 15-59 years old Italians accounted for 61,1% of the total in 2000, this percentage feature will drop in 2050, when this category ere will account for be less than 50% of the people. The same downward trend is expected for 0-14 years old peoppole, whereas the amount of Italians aged more than 60 will significantly rise (growing from 24.1% to 42.3%).

Hi, I'm no native speaker (but I have a CAE certification, which if I'm not wrong is about the same level as IELTS) so I am just 99% sure of the corrections but I hope this helps anyway :). My corrections are in yellow, my comments in green.

IELTS writing task 1... describing a bar graph!