Oliver Coombes compiled a list of Studio Ghibli's domestic grosses at the appendix to his Pom Poko essay (see links). I decided to reprint the list here, with a few alterations. One, I consulted Box Office Mojo for The Cat Returns' grosses. Unfortunately, their records only go back a few years, so I couldn't obtain numbers for anything before 2002.
Also, I converted the numbers into US Dollars, using the current exchange rate of $1 = 118.778 Yen. One major caveat - I don't know if these numbers were adjusted for inflation. Probably not. I think these were the final tallies at the time, or numbers that are very close.
In any case, caveat emptor. Don't quote these numbers as if they're the Gospel. I'm only showing these numbers as a comparison, and as an education tool.
One additional note: I wasn't able to find numbers for My Neighbor Totoro and Grave of the Fireflies, which appeared in Japan as a double bill. Coombes writes that the numbers were still below Nausicaa, and it's well known that they didn't earn a profit.
Also, I haven't found any numbers for 1995's Mimi wo Sumaseba (Whisper of the Heart). I am aware that the movie was a hit, enough so that tour guides started offering tours of the sights from the movie (set in suburban Tokyo).
The first Ghibli movie to turn a profit was Kiki's Delivery Service in 1989. Since then, every film has become the top-grossing domestic film for its year. Most of the time, the American movies drew the largest audiences, although Takahata is proud that his Pom Poko beat out Disney's The Lion King in 1994.
Ghibli's winning streak was only broken in 1999, when My Neighbors the Yamadas went over like a lead balloon. Unfairly, I might add. Again, kids, everybody in Japan preferred to spend the summer with...Jar Jar. Ugh. What were they thinking?!
Studio Ghibli Domestic Grosses (US Dollars; $1 = 118.778 Yen)
1984 - Nausicaa of the Valley of Wind - 6, 230, 110
1986 - Laputa: Castle in the Sky - 4, 883, 059
1988 - My Neighbor Totoro - n/a
1988 - Grave of the Fireflies - n/a
1989 - Kiki's Delivery Service - 18, 100, 955
1991 - Omohide Poro Poro - 15, 575, 275
1992 - Porco Rosso - 23, 573, 389
1993 - Umi Ga Kikoeru - television
1994 - Pom Poko - 22, 142, 148
1995 - Whisper of the Heart - n/a
1997 - Mononoke Hime - 162, 488, 003
1999 - My Neighbors the Yamadas - 6, 903, 365
2001 - Spirited Away - 255, 939, 652
2002 - The Cat Returns - 50, 590, 057
2004 - Howl's Moving Castle - 159, 962, 283
1984 - Nausicaa of the Valley of Wind - 6, 230, 110
1986 - Laputa: Castle in the Sky - 4, 883, 059
1988 - My Neighbor Totoro - n/a
1988 - Grave of the Fireflies - n/a
1989 - Kiki's Delivery Service - 18, 100, 955
1991 - Omohide Poro Poro - 15, 575, 275
1992 - Porco Rosso - 23, 573, 389
1993 - Umi Ga Kikoeru - television
1994 - Pom Poko - 22, 142, 148
1995 - Whisper of the Heart - n/a
1997 - Mononoke Hime - 162, 488, 003
1999 - My Neighbors the Yamadas - 6, 903, 365
2001 - Spirited Away - 255, 939, 652
2002 - The Cat Returns - 50, 590, 057
2004 - Howl's Moving Castle - 159, 962, 283