statistics--Telarge do you feel this is accurate?

Came across this table and was surprised to find that it was so widespread. It seems that this info was gathered in 1998. If true, what is unique about Gambella? Why do they not practice FGM?
Table 1
Prevalence of different Harmful traditional practices (HTP) in different regions of Ethiopia
(in percentages)
Region: FGM/ Milk teeth extraction/Uvulectomy/Soiling umbilical Cord/ Incision
Tigray 48.1 /52.4/ 92.8/ 67.2/ 37.9
Afar 94.5/ 71.7/ 65.7 /60.3/ 38.8
Amhara 81.1 /45.8/ 62.8/ 45.9/ 30.5
Oromiya 79.8/ 28.0/ 48.5/ 70.8/ 11.9
Somali 69.7/ 73.4/ 93.2/ 0.3/ 6.5
Benishangul 52.9/ 23.1/ 26.8/ 82.5/ 32.6
SNNPR 46.3/ 52.3/ 59.8/ 48.3/ 18.1
Gambella 0.0/ 91.1/ 25.4/ 60.4/ 50.0
Harari 81.2/ 36.3/ 70.4/ 44.4/ 4.6
Addis Ababa 70.2/ 17.6/ 42.3/ 21.6/ 4.8
Ethiopia 73.6/ 59.5/ 40.4/ 49.6/ 18.0

Found this table on this site: http://ukwangela.ki.se/Addiskurs/Studpres/htp.html