In order to estimate shelter cost inflation, BLS collects Rent data from a sample of renters for the Consumer Price Index. Each rental unit is interviewed every six months; in each interview, the respondent is asked what the rent is in the current month and what the rent was in the previous month. One-month rent relatives are calculated using these reported rent values; six-month rent relatives are computed using current month rent data from preceding interviews. This paper gives the results of an exploratory data analysis based on rent data from 1992 through 1996. The results indicate that the proportion of six-month rent changes increases and the proportion of one-month rent changes decreases as the collection date increases throughout the month. Variances are computed using the stratified random-groups method, to test the significance of these trends. More recent data (from 1997 and 1998) is used to determine if these results hold in later time periods. Possible (psychological) explanations of the phenomena are considered.