In most subject areas, the proportion of women PhD students is around 50%. Mathematics differs despite minimal differences between boys’ and girls’ school achievements. In this paper, we show, drawing on Swedish data from the last 45 years, that low female participation in mathematical PhDs is due to low participative growth rates rather than historical low levels. In comparison, science has twice as strong growth rate, while non-STEM subjects have grown four times faster. The results show that gender differences regarding participation is indeed dynamic, but changes do not occur despite political initiatives such as laws on non-discrimination and encouragement of equal parental leave. Instead, the results imply that in order for maths departments to avoid continuing being gendered institutions, it requires active changes in structures and working environment.