In this Q, the main title for bar graph is written "from 1970 to 1982 and median sale price for SELECTED YEARS "
in above Q-25 they are asking 1970 to 1975 that means 1971,1972,1973,1974 & 1975 to why greg have seen only 1970 and 1975
The question is pertaining to the second graph, and consists only for two years, namely 1970 and 1975. There is nothing in that graph about 1971 - 1974, and hence there is nothing to consider as a result.