I think much more than 30% - what were easy to afford or easier to afford tenement apartments rents had gone from lets use a base of $250. per to $1100. per, to now $3000. per month. And
these apartments were often sub-divided into studios or Jr. One Bedrooms for those prices. Giuliani raised property taxes then Bloomberg raised them by almost double from there to fill the city coffers.
My office lease went from reasonable $'s per month to unreasonable $'s in the course of 6 months - a terrible lease agreement back in 1990 cause that to happen but we needed to be in that building
for a reason. Oh well. I had us move to a better location for better $'s almost immediately. It took that building several years to find someone to take the space we vacated.
The greed of landlords coupled with the mayor's needs to see financial health of the city through property taxes along with tax breaks for the big corporate players on Wall st.