Writing Feedback / How should I describe all types of graphs,diagrams or charts? [8]

Hello
I really need your help because in a week I have an exam at English and I have to describe some graphs.
Here is an example of a description of a graph an table made by me :

Te main topic of the graph and table is society and social issues. They show the people found guilty or cautioned in 2000 as a percentage of a population by gender and age, in England and Wales.

As it can be seen from the graph the number of the 18-year-old male offenders reached a peak of over 7 percent of all. While the number of the 20-year-old females found guilty or cautioned had the highest level of approximately 2 percent, which ...

The main topic o the graph and table is society and social issues. They show the people found quilty or cautioned in 2000 as a percentage of population by gender and age, in England and Wales.The percentage of commited crimes increased dramatically and sharply in the same time, in that period of time. As a consequence, both human beings and society itself wre drastically affected, becoming much more violent in various types of offence. These facts are shown by the statistics made during that year.

The graph shows very clearly that during 2000 year, the males committed far more crimes in contrast to females. For example, the number of 18-year-old male offenders reached a peak of 7 percent of all. While the number of females found quilty or cautioned had the hiest level of approximately 2 percent, which means almost three times less than the percentage of male offenders. But after the age of 20, the number of both genders declined steadily.

As can be seen from the graph, with age(i mean the people who are getting older and older, i don't remember the specific collocation) females found quilty or cautioned committed less and less/ fewer and fewer crimes. In comparison to 20-year-old femlae offenders, 30-year-old female offenders had an almost insignificant number of committed crimes, such as 0.5 per cent. Also male offenders with age committer fewer and fewer crimes, so that there was a tiny percentage of people being 70 years and over committed a crime.

In England and Wales there were recorded many types of offence suring the period 1991 and 2001. The number of these types of offence was unfortunately very high, especially the number of thefts. The statistics from the table indicate the fact that between 1991 and 2001 the number of thefts including car thefts was dramatically higher than the number of the other crimes. Over the period of 1991-2001 the total number of thefts stood at just 2 million. Between 1991 and 2001 there was an overall decrease in the number of recorded crimes.

Taking everything into consideration the percentage of the number of both offenders and types of offence decreased after 2000.

It seems to me that this description is simple. I do not know which are the rules.
They said to me that it is advisable to:
- divide your report into paragraphs
- end your report with one or two sentences summarising the most important trends
- use a range of grammatical structures and vocabulary
- use formal language
- use linking words or phrases between sentences and paragraphs were appropriate
- vary the way you describe figures by using percentages, functions and ratios

I think it is a little bit colourless . Should I add some colour? because I can do that, if is neccessary.

thank you