Diagram of the fractional period change ΔP/P versus the angular velocity Ω of the active component star for CVs according to Table 2. The position of EX Dra is indicated by a cross, the other long-period CVs, short-period CVs and pre-CVs in the period gap are denoted by dots, circles, and open squares, respectively. The best linear fit to data above the period gap derived by Borges et al. (2008) ΔP/P ∝ Ω^-0.7 is indicated by the dot-dashed line.