Are they having enough sleep?

The above table is taken from ST

 Overall children in Spore sleeps late compare to the children in western countries. For examples, my fren's kids, they slept at 730pm. Whereas for us, we reach home ard 730pm.....

What is the normal bedtime for your kids? P goes to bed ard 930pm and fall asleep at ard 10pm and wake up ard 745am. She will have a 2h nap in cc, in total she has at least 11.5 h of sleep a day during weekday. Whereas on wkend, her clock will go haywire, she will sleep ard 11pm and up ard 9-10am and totally miss her afternoon nap. Overall on wkend she will sleep lesser.

Research also shows that sleeping less will make a person stupid, and i think tt is happening to me.