I suppose at first we collect a bit and then make an order.

It must be let's say: -12 and more & the player must have been Top-200 for at least one week of the year and 4 WTA-Tournaments (Q or MD).
01. Roesch, Angelika (GER/2003) 10-34 = -24
02. Kleinova, Sandra (CZE/1998) 14-38 = -24
03. Müller, Martina (GER/2003) 7-28 = -21
04. Sfar, Selima (TUN/2005)
14-34 = -20
05. Serra-Zanetti, Antonella (ITA/2006)
3-22 = -19
06. Lubiani, Francesca (ITA/2003)
9-27 = -18
07. Bremond, Severine (FRA/2007)
12-30 = -18
08. Spears, Abigail (USA/2005)
6-23 = -17
09. Marrero, Marta (ESP/2005)
6-22 = -16
10. Weingärtner, Marlene (GER/2002)
10-26 = -16
10. Birnerova, Eva (CZE/2006)
10-26 = -16
12. Andretto, Laurence (FRA/2000)
13-29 = -16
13. Zarska, Anna (POL/2000)
14-30 = -16
14. Benesova, Iveta (CZE/2003)
20-36 = -16
15. Jeyaseelan, Sonya (CAN/2001)
3-18 = -15
16. Pisnik, Tina (SLO/2004)
10-25 = -15
17. Pastikova, Michaela (CZE/2005)
13-28 = -15
18. Kandarr, Jana (GER/2002)
14-29 = -15
18. Kurhajcova, Lubomira (SVK/2005)
14-29 = -15
20. Serra-Zanetti, Adriana (ITA/2004)
16-31 = -15
21. Hopkins, Jennifer (USA/2002)
17-32 = -15
22. Bes, Eva (ESP/2002)
9-23 = -14
23. Henke, Vanessa (GER/2007)
11-25 = -14
24. Stevenson, Alexandra (USA/2003)
13-27 = -14
25. Kremer, Anne (LUX/2005)
17-31 = -14
26. Schruff, Julia (GER/2006)
20-34 = -14
27. Vento-Kabchi, Maria (VEN/2006)
7-20 = -13
28. Montolio, Angeles (ESP/2002)
11-24 = -13
29. Leon-Garcia, Gala (ESP/2002)
12-25 = -13
30. Jidkova, Alina (RUS/2005)
15-27 = -12
31. Serra-Zanetti, Adriana (ITA/2000)
16-28 = -12
32. Garcia, Paula (ESP/2005)
19-31 = -12