However, women overruntook men in the 90’s with a substantial difference of about 100 thousand students.

The negative connotations of "to overrun" (invading, infesting) make the presence of more women sound like a bad thing. I'd replace it with "to overtake" because it has a neutral meaning: "to catch up with".

In part-time education, there wasere twice as many men thanas women in the 70’s, howeverbut the number of students reached a balance in the 90’s.

I changed "however" to "but" in my correction, but there are other options for connecting these two thoughts.

Use a semicolon and comma: "...in the 70s; however, the number..."

Start a new sentence and add a comma: "...in the 70s. However, the number..."

Future Education in Britain inAcross Three Periods of Time

The line graph illustrates the quantitiesamount of male and female students in further education in Britain in decades ofthe 70’s, 80’s and 90’s, and the proportion between full-time and part-time forms of education.

"amount" sounds better here than "quantities"

Overall, the graph is separated to left and right halves with lineswith lines on the left and right representing men and women respectively.

The full-time number for men fluctuated over three decades, whereas for women i, the amount made a steep rise during the second and third decades.

sounds better like this

The part-time education number grew for both genders, with a jump for female students in athe period between the 70’s and 80’s.

Male students were predominant in 70’s, overtaking women by more over thanthan over 200 thousand.

With a decrease in male students, the 80’s saw an approximate balance between sexes.

However, women overrun men in the 90’s with a substantial difference of about 100 thousand students.

There also was a littlewas also a small increase in number of male students in the 90’s, but it wasn’t as significant as femalethe grown in female students.

In part-time education, there was twice as many men than women in the 70’s, however the number of students reached a balance in the 90’s.

The line graph illustrates the quantities of male and female students in further education in Britain in decades ofduring the 70’s, 80’s and 90’s and the proportion between full-time and part-time forms of education.

Overall, the graph is separated to left and rightplit in two halves, with lines on the left and the right representing men and women respectively.

The part-time education number grew for both genders, with a jump for female students in athe period between 70’s and 80’s.

Male students were predominant in the 70’s overtaking women more over than 200 thousand.

With a decrease in male students, the 80’s saw an approximate balance between sexes.

However, women overrun men in the 90’s with a substantial difference of about 100 thousand students.

There also was a little increase in the number of male students in the 90’s, but it wasn’t as significant as female.

In part-time education, there wasere twice as many men thanas women induring the 70’s, however the number of students reached a balance in the 90’s.

Future Education in Britain inAcross Three Periods of Time

You could also say 'over three periods'. But 'across' sounds like a better register for this text.

The line graph illustrates the quantities of male and female students in furthigher education in Britain in decades ofthe 70’s, 80’s, and 90’s, and the proportion between full-time and part-time forms of education.

The comma following 80s isn't necessary but adds clarity.

Overall, the graph is separated into left and right halves with lines representing men and women respectively.

The part-time education numbers grew for both genders, with a jump for female students during a period betweenin the 70’s and 80’s.

'Between the 70s and 80s' also makes sense, but I like the sound of mine better.

Male students were predominant in 70’sthe 70s, overtaking women by more over than 200 thousand.

by more than 200k = by over 200k

With a decrease in male students, the 80’s saw an approximate balance between sexes.

However, women overruan men in the 90’s with a substantial difference of about 100 thousand students.

There also was a little increase in the number of male students in the 90’s, but it wasn’t as significant as for females.

In part-time education, there wasere twice as many men than women in 70’s,the 70s; however, the number of students reached a balance in the 90’s.