For such a sucessful show.... why were the episode orders so low? I can understand for Mid-Season but what about the other seasons?

Season 1: 6 Episodes
Season 2: 25 Episodes
Season 3: 22 Episodes
Season 4: 25 Episodes
Season 5: 22 Episodes
Season 6: 28 Episodes
Season 7: 22 Episodes
Season 8: 22 Episodes
And it only adds up 172 Episodes, and the show ran for 8 years?? I mean if I was a Network President I would order at least 26 - 28 Episodes per- season?? I wonder why this is?

I think the 6 episodes REALLY brought it down.

But here, the usual episode order is 22. Not many shows get 26-28 eps per season. But I agree, 4 seasons only have 22. Hm.. probably someone will answer this better than me. lol.