select cast(amc as decimal(15, 4)) / cast(pmc as decimal(15, 4)) am_pm_ratio
from (select count(*) amc
      from web_sales,
           household_demographics,
           time_dim,
           web_page
      where ws_sold_time_sk = time_dim.t_time_sk
        and ws_ship_hdemo_sk = household_demographics.hd_demo_sk
        and ws_web_page_sk = web_page.wp_web_page_sk
        and time_dim.t_hour between 8 and 8 + 1
        and household_demographics.hd_dep_count = 6
        and web_page.wp_char_count between 5000 and 5200) at1,
     (select count(*) pmc
      from web_sales,
           household_demographics,
           time_dim,
           web_page
      where ws_sold_time_sk = time_dim.t_time_sk
        and ws_ship_hdemo_sk = household_demographics.hd_demo_sk
        and ws_web_page_sk = web_page.wp_web_page_sk
        and time_dim.t_hour between 19 and 19 + 1
        and household_demographics.hd_dep_count = 6
        and web_page.wp_char_count between 5000 and 5200) pt
order by am_pm_ratio limit 100
