A Party member's life condensed in 12 ledger books

Cigarette brands

"Income and consumption records provide much information," Liu said. "They show us how the man lived, what he bought for daily use, as well as what he ate and drank."

For example, Zhang recorded every packet of cigarettes he bought, including its price, size and brand. A glimpse at the 41 years shows at least 40 brands of cigarettes that Zhang smoked, varying from decade to decade. In the 1950s, he smoked the brands Daqianmen and Sanmenxia. In the 1960s, he smoked a brand named Shanghai, switching to a brand called Albania in 1968. Later, he would go on to roll his own cigarettes.

Clearly a different era than today, but the brands he smoked actually reflected achievements and trends across China at those times.

In 1957, the Sanmenxia Dam on the Yellow River started construction and was put into use four years later. In the 1950s and 60s, Shanghai's role as the industrial base of the nation was so significant that many brands carrying its name emerged, including the bicycle, the watch and the cigarette.

The Albania brand was actually not a brand but mistaken for one because China imported a large number of cigarettes from the nation in the late 1960s, which were so popular that many people rushed to buy them.

In the 1970s, among Zhang's records were purchases of rolling tobacco, something commonly associated with those in economic difficulty due to its cheaper cost.

"It's noticeable that he only smoked the relatively cheap cigarettes," said Liu. "Zhang once served a position at the vice-provincial level, which is a quite high rank in the bureaucratic system, yet he had been leading a simple life in a virtuous way."