From what I observed in my school, the first promotion from GEO2-3 is the same around 2009 or after 2011 batch.

GEO 3-4 varies on the performance of the officers. Have female officers promoting to geo 4 in their 5th year, at 29, to male officers Geo 4 in their 6th year despite getting Geo 3 faster. There are also officers who are stuck donkey years at Geo 3.

For Geo 4- geo 5, I admit the trend in my school is it takes longer. Promotion is not any faster , even for KP at geo 4 for a few years. Same goes for geo 5-seo1