Percentage change of cystic glandular hyperplasia turning to malignancy:
As discussed in the preceding text:
Endometrial hyperplasia is of the following four varieties:

Simple hyperplasia without atypical cells
Complex hyperplasia without atypical cells
Simple hyperplasia without atypical cells
Complex hyperplasia without atypical cells.

Logically speaking least chances of malignant transformation are with simple hyperplasia without atypia and maximum chances are with complex hyperplasia with atypia.
Chances of Progression to Carcinoma:
Type of hyperplasia

Simple without atypia - 1%°
Complex without atypia - 3%°
Simple with atypia - 8%°
Complex with atypia - 29-30%°
Thus, from the table, it is reaffirmed that minimum chances of progression to carcinoma are with simple hyperplasia without atypia ( also called as cystic glandular hyperplasia )and maximum chances of carcinoma are with complex hyperplasia with atypia.
0.10%
2%
1%
10%