Finally, we select the fourth reference month for each wave10, and use the last weeks' employment status, which corresponds to the standard CPS employment measure.
The fourth reference month of 1990, wave 1 covers January through April 1990, just before the recession of 1990/1991 and the expansion of the DI program started11.
The fourth reference month of 1996, wave 2 covers July through October 1996, a time when the major expansion of the early 1990s had subsided.
The average number of deaths per day for the road dust period (November through May) was 29.6 (range, 13 52), and for the reference season (June through October) was 26.8 (range, 12 50).
Also, for the reference period June through October, changes in effect estimates were small after adjustments for CO and O3.
The BBC, in its initial response to Hitchens, had said the programme's tone was "deliberately irreverent and provocative" but admitted it had created a "misleading impression" by removing the reference to May Day.
The protests, as well as Mr. Abe's resignation and his replacement by Prime Minister Yasuo Fukuda, a moderate, led the Ministry of Education to put back most of the references in December.
Taking the month of December as the reference period, the monthly (seasonal) dummy variables are significant during the months of February ,March, May, June, July, and October.
Qualitative histological grading provided the reference standard for qualitative OCT-based assessment of matched OCT images.
