There is a hard limit to growth....for China it was 10-12% for India it is 8%....the difference is due to the authoritative Chinese govt and the 22 point difference in average IQ between the two populations (partly genetic, partly due to nutrition, partly due to hygiene,partly due to vaccination and parasitic load)
even if we grow at breakneck speed , we won't become a developed country for another 30 years..........that is if we grow at breakneck speed in the first place (8%)....for that we need more rationality and scientific mindset, less of spirituality,religion,superstition, belief in ghosts, belief in yogic supernatural powers, belief in astrology
We have to see what growth Modi achieves in the last 2 years of the first term...that would become more or less our benchmark for the next 30 years.
@Kaptaan already explained the discrepancy... I have added the world bank website link to the original post