Women having a first child was low in both years (1995 and 2005).
Women was low(?!) Here we have some subject/verb disagreement, and so I’m guessing that it was actually a different singular countable noun that was low, and not ‘women‘!
Your opening theme was ‘women‘. If the women you mention were indeed low then this could mean several things (click for captions):
When you’re describing numbers, you must describe numbers. Remember that numbers are represented by statistics words: number, amount, percentage,rate, ratio, etc. If you do not use one of these words then your writing becomes very difficult to follow, and obviously this affects your IELTS score.